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  • Immunocytochemistry  (70)
  • Zea mays  (50)
  • pH  (44)
  • Springer  (163)
  • American Physical Society (APS)
  • Elsevier
  • Molecular Diversity Preservation International
  • Public Library of Science
  • 2015-2019
  • 1995-1999  (163)
  • 1940-1944
  • 1995  (163)
  • 1943
Collection
Keywords
Publisher
  • Springer  (163)
  • American Physical Society (APS)
  • Elsevier
  • Molecular Diversity Preservation International
  • Public Library of Science
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Years
  • 2015-2019
  • 1995-1999  (163)
  • 1940-1944
Year
  • 1
    Electronic Resource
    Electronic Resource
    Inheritance of resistance in maize silks to the corn earworm (1995)
    Springer
    Entomologia experimentalis et applicata 77 (1995), S. 315-321 
    Details
    ISSN: 1570-7458
    Keywords: Insecta ; Helicoverpa zea ; Zea mays ; resistance inheritance ; joint scaling test ; additive-dominance model
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The corn earworm,Helicoverpa zea (Boddie), is a perennial economic pest of field crops in the United States. Maize,Zea mays L., is the major host crop promoting the build-up of devastating corn earworm populations that limit full production of cotton, soybean, peanut, and grain sorghum. Resistance to the corn earworm in maize and in particular sweet maize, would provide an environmentally safe, economical method of control for this pest insect. Antibiotic effects of corn silks on this insect are: small larvae, extended developmental period, and reduced fecundity. Silks from individual maize plants of resistant and susceptible lines and progeny in six generations consisting of parents (P1, P2), F1, F2, and backcrosses BC1.1 (F1 × P1) and BC1.2 (F1 × P2) from each of four crosses were used to determine the genetic basis of the antibiotic resistance of silks to the corn earworm. In the cross of Zapalote Chico × PI340856, genes controlling resistance in the silks to the corn earworm larvae are dominant in PI340856 to those in Zapalote Chico. The cross of Zapalote Chico × GT114 involves parents differing in degree of resistance, and possibly differing for the genetic mechanism by which the resistance is inherited. The inheritance of resistance may involve non-additive (dominance and epistasis) genetic variance. A digenic 6-parameter model indicated (1) the resistance in this cross is controlled by more than one pair of genes and (2) some or all of the genes interact to cause non-allelic interaction. Thus, the resistance in this cross may be controlled by both dominant and recessive genes. The resistance of Zapalote Chico × CI64, an intermediate inbred, is influenced by additive gene effects. The digenic model adequately predicts all generation means of the cross of GT3 × PI340856 except for the F1. Thus, it appears that the additive-dominance model is not satisfactory for this cross involving susceptible and resistant parents. Generation mean analysis indicates that resistance to silk-feeding by corn earworm larvae is under genetic control, but gene action differs from one type of cross to another.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02383066
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  • 2
    Electronic Resource
    Electronic Resource
    The stability of 12-molybdosilicic, 12-tungstosilicic, 12-molybdophosphoric and 12-tungstophosphoric acids in aqueous solution at various pH (1995)
    Springer
    Catalysis letters 34 (1995), S. 237-244 
    Details
    ISSN: 1572-879X
    Keywords: metal-oxygen cluster compounds ; heteropoly acids ; stability ; pH ; aqueous solutions
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The stabilities of the solid superacids H3Mo12O40, H3PW12O40, H4SiMo12O40 and H4SiW12O40 in aqueous solution have been measured at various values of pH by use of ion chromatographic analyses. The aforementioned acids are completely decomposed at values of pH, 4.0, 5.2, 7.0 and 11.0, respectively. The stabilities in aqueous solution with respect to pH follow the order H4SiW12O40 〉 H3PW12O40 〉 H4SiMo12O40 〉 H3PMo12O40.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00808338
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  • 3
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    Effects of a vesicular-arbuscular mycorrhizal fungus and other soil microorganisms on growth, mineral nutrient acquisition and root exudation of soil-grown maize plants (1995)
    Springer
    Mycorrhiza 5 (1995), S. 321-327 
    Details
    ISSN: 1432-1890
    Keywords: Glomus mosseae ; Zea mays ; Mineral uptake ; Root exudation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Maize (Zea mays L. cv. Alize) plants were grown in a calcareous soil in pots divided by 30-μm nylon nets into three compartments, the central one for root growth and the outer ones for hyphal growth. Sterle soil was inoculated with either (1) rhizosphere microorganisms other than vesicular-arbuscular mycorrhizal (VAM) fungi, (2) rhizosphere microorganisms together with a VAM fungus [Glomus mosseae (Nicol. and Gerd.) Gerdemann and Trappel], or (3) with a gamma-irradiated inoculum as control. Plants were grown under controlled-climate conditions and harvested after 3 or 6 weeks. VAM plants had higher shoot∶root ratios than non-VAM plants. After 6 weeks, the concentrations of P, Zn and Cu in roots and shoots had significantly increased with VAM colonization, whereas Mn concentrations had significantly decreased. Root exudates were collected on agar sheets placed on the interface between root and hyphal compartments. Six-week-old VAM and non-VAM plants had similar root exudate compositions of 72–73% reducing sugars, 17–18% phenolics, 7% organic acids and 3% amino acids. In another experiment in which root exudates were collected on agar sheets with or without antibiotics, the amounts of amino acids and carbohydrates recovered were similar in VAM and non-VAM plants. However, threeto sixfold higher amounts of carbohydrates, amino acids and phenolics were recovered when antibiotics were added to the agar sheets. Thus, the high microbial activity in the rhizosphere and on the rhizoplane limits the exudates recovered from roots.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00207404
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  • 4
    Electronic Resource
    Electronic Resource
    Effects of a vesicular-arbuscular mycorrhizal fungus and other soil microorganisms on growth, mineral nutrient acquisition and root exudation of soil-grown maize plants (1995)
    Springer
    Mycorrhiza 5 (1995), S. 321-327 
    Details
    ISSN: 1432-1890
    Keywords: Key words Glomus mosseae ; Zea mays ; Mineral uptake ; Root exudation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Maize (Zea mays L. cv. Alize) plants were grown in a calcareous soil in pots divided by 30-μm nylon nets into three compartments, the central one for root growth and the outer ones for hyphal growth. Sterile soil was inoculated with either (1) rhizosphere microorganisms other than vesicular-arbuscular mycorrhizal (VAM) fungi, (2) rhizosphere microorganisms together with a VAM fungus [Glomus mosseae (Nicol. and Gerd.) Gerdemann and Trappel], or (3) with a gamma-irradiated inoculum as control. Plants were grown under controlled-climate conditions and harvested after 3 or 6 weeks. VAM plants had higher shoot : root ratios than non-VAM plants. After 6 weeks, the concentrations of P, Zn and Cu in roots and shoots had significantly increased with VAM colonization, whereas Mn concentrations had significantly decreased. Root exudates were collected on agar sheets placed on the interface between root and hyphal compartments. Six-week-old VAM and non-VAM plants had similar root exudate compositions of 72–73% reducing sugars, 17–18% phenolics, 7% organic acids and 3% amino acids. In another experiment in which root exudates were collected on agar sheets with or without antibiotics, the amounts of amino acids and carbohydrates recovered were similar in VAM and non-VAM plants. However, three- to sixfold higher amounts of carbohydrates, amino acids and phenolics were recovered when antibiotics were added to the agar sheets. Thus, the high microbial activity in the rhizosphere and on the rhizoplane limits the exudates recovered from roots.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s005720050079
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  • 5
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    Bioavailability of heavy metals and abundance of arbuscular mycorrhiza in a soil polluted by atmospheric deposition from a smelter (1995)
    Springer
    Biology and fertility of soils 19 (1995), S. 22-28 
    Details
    ISSN: 1432-0789
    Keywords: Arbuscular mycorrhiza ; Limed silty loam Heavy metals ; Pb-Zn smelter ; Root colonization Spore numbers ; Tolerance ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The bioavailability of heavy metals (Cd, Zn, Pb, Cu) and the abundance of arbuscular mycorrhiza (AM) were studied in two agricultural fields close to a Pb-Zn smelter and three fields outside the pollution zone all cultivated with maize (Zea mays L.). Metal extractability with ethylenediaminetetraacetic acid (EDTA)-NH4OAc and Ca(NO3)2, plant metal uptake, and mycorrhizal parameters (spore number, root colonization) were assessed at two growth stages (six-leaf and maturity). Despite regular liming, the availability of Cd, Zn, and Pb was markedly higher in the two metal-polluted fields than in the three uncontaminated fields. However, the AM abundance was not correlated with metal availability. Root colonization and spore numbers in the metal polluted fields were relatively high, though at plant maturity the former was significantly lower than in one of the uncontaminated fields. The very low AM abundance in the two other unpolluted fields was related to other factors, particular soil and plant P status and soil pH. AM root colonization did not substantially prevent plant metal accumulation, since the metal concentrations in maize grown on the polluted fields strongly exceeded normal values, and for Cd and Pb reached the limits of toxicity for animal feed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00336342
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  • 6
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    Soil microbial biomass and organic matter composition in soils under cultivation (1995)
    Springer
    Biology and fertility of soils 19 (1995), S. 197-202 
    Details
    ISSN: 1432-0789
    Keywords: Soil organic matter ; Cultivation ; CPMAS 13C-NMR ; Microbial biomass ; Substrate-induced respiration ; Alkylic carbon ; pH
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract To determine whether there is a relationship between the composition of soil organic matter and the activity of the soil microbial biomass, the composition of the organic matter in 12 typical arable soils in Northwest Germany was investigated by wet chemical analysis and CPMAS cross polarization magic angle spinning 13C-NMR spectroscopy. The data were correlated with the microbial biomass as estimated by substrate-induced respiration. A strong correlation between the microbial biomass and alkylic C compounds was observed (r=-0.960***). Recalcitrant substances were enriched in this fraction, which were classified as humic acids according to the wet chemical procedure. The microbial decomposition of these humic acids is probably retarded, due to their chemical structure and/or physical bonding, when the soil microbial biomass activity is limited.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00336159
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  • 7
    Electronic Resource
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    Nitrogen use in maize-grain legume cropping systems in semi-arid Kenya (1995)
    Springer
    Biology and fertility of soils 20 (1995), S. 57-62 
    Details
    ISSN: 1432-0789
    Keywords: Nitrogen use ; Nitrogen fertilizer recovery ; Zea mays ; Phaseolus vulgaris ; Vigna unguiculata ; Nitrogen fixation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Locally suitable cultivars of maize, beans, and cowpeas were grown in field experiments for four seasons in semi-arid Kenya. For three seasons, the dry matter production and grain yield of maize and beans were not increased by N fertilizer additions up to 120 kg N ha-1. Fertilizer recoveries measured by 15N isotope dilution techniques were low, less than 20%. Inoculated and uninoculated beans failed to fix N2. By contrast the cowpea derived 50% of its N from fixation, equivalent to 197 kg N ha-1. The N content of the grain generally exceeded 40 kg N ha-1, and the N content of the seeds from the grain legumes were greater than those from the cereals. Large inputs of N fertilizer or N by fixation are required if maize-grain legume cropping system in semiarid Kenya are to be sustained in the long term.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00307842
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  • 8
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    Proton-activated currents in chick spinal motoneurons (1995)
    Springer
    Journal of comparative physiology 177 (1995), S. 503-510 
    Details
    ISSN: 1432-1351
    Keywords: pH ; Patch clamp ; Glutamate receptors
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Proton-activated currents were examined in patch-clamp recordings from embryonic chick motoneurons. Rapid application of protons evoked a large inward current that peaked and then decayed, presumably due to channel inactivation. A pH shift from 7.4 to 7.1 was sufficient to evoke detectable currents. The shift from pH 7.4 required for half-maximal current amplitude (EC50) was to pH 6.8. In single-channel recordings, activation was achieved within 6 ms at pH 7. The average channel open time was 1.4 ms; the closed-state time constants were 1.0 and 6.2 ms. At pH 6.5, the single-channel conductance was 22 pS, and the reversal potential was similar to the calculated Na+ equilibrium potential. Current amplitude declined by 49% following addition of Ni2+ and increased by 58% as Ca2+ was lowered from 2 to 0.1 mM. Inactivation time constants ranged from 90 to 200 ms as pH varied from 6 to 7; these values did not depend on membrane potential. The reactivation time constant was 22 s. Proton- and glutamate-activated currents summated. Thus, transient decreases in extracellular pH can evoke large inward currents that decay rapidly and reactivate slowly. These currents may occur under pathological conditions that affect extracellular pH.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00187485
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  • 9
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    Aminated polystyrene membranes for a fiber optic pH sensor based on reflectance changes accompanying polymer swelling (1995)
    Springer
    Microchimica acta 121 (1995), S. 41-50 
    Details
    ISSN: 1436-5073
    Keywords: polystyrene membranes ; fiber optics ; pH ; reflectance ; aminated polystyrene
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract We have prepared toughened, porous, aminated polystyrene membranes that undergo an increase in reflectance as the pH increases from 6.8 to 8.0. Vinylbenzyl chloride (VBC) is copolymerized with divinylbenzene (DVB) in the presence of a toughening agent, Kraton G1652, a styrene-ethylene, butylene-styrene triblock copolymer, and a porogenic solvent, xylene/ dodecane. The optimum formulation for sensing is 2% DVB (mol DVB/mol VBC), 2% Kraton (g Kraton/g VBC) and 40% (v/v) 2∶1 xylene: dodecane. Benzoyl peroxide is used as the initiator. The components are partially polymerized at 85 °C to a viscosity of 600–800 centipoise. The polymerization is then stopped by reducing the temperature. A drop of the partially polymerized solution is confined between two microscope slides and the polymerization reaction is completed. The resulting membrane is then swollen in 1,4-dioxan and reacted with diethanolamine. These membranes have been incorporated into a pH sensor based on changes in reflected intensity measured through a bifurcated bundle of twenty unbuffered 50/55 core/cladding glass-on-glass optical fibers with numerical apertures of 0.57. The resulting sensor is stable and requires inexpensive optical components, a red-emitting LED as the source and a silicon photodiode as the detector.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01248239
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  • 10
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    Infection and disintegration of vascular tissues of non-suberized roots of spruce byHeterobasidion annosum and use of antibodies for characterizing infection (1995)
    Springer
    Mycopathologia 129 (1995), S. 91-101 
    Details
    ISSN: 1573-0832
    Keywords: ELISA ; Endodermis ; H. annosum ; Immunocytochemistry ; Root rot ; Vascular tissues
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Vascular disintegration mainly of medulla rays of spruce roots is of major significance in root rot disease of spruce caused byH. annosum. Using seedling roots as an experimental model, the possible routes and initial host reactions preceding invasion of vascular tissues was investigated. Transmission electron microscopy showed that penetration through the endodermis was an obvious route but not without host resistance. Using antibodies againstH. annosum hyphal materials, some labelling of vascular tissues remote from sites of fungal colonization suggest the release of fungal secretory products partly active in tissue disintegration. Similarly, intense labelling was also observed in severely colonized host tissues at late stages of infection. Strong labelling recorded at 3 d p.i. mainly on fungal hyphae and scant gold particles on invaded host tissues could imply that induction of host antifungal metabolites may have been a late event. A correlation was found between total antigenic material in root homogenates measured by ELISA, density of tissue labelling by immunocytochemistry and severity of disease symptoms. The importance of this in relation to diagnosis of biotic root rot diseases in the field is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01103468
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  • 11
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    Enterobacter cloacae is an endophytic symbiont of corn (1995)
    Springer
    Mycopathologia 129 (1995), S. 117-125 
    Details
    ISSN: 1573-0832
    Keywords: Biological control ; Corn seedling disease ; Enterobacter cloacae ; Fusarium moniliforme ; Maize ; Seedling blight ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The bacteriumEnterobacter cloacae is presently used for biocontrol of postharvest diseases of fruits and vegetables and as a preplant seed treatment for suppression of damping-off. This bacterium has apparent affinities for several grass species, but it is not considered to be an endophyte. While screening corn for fungi and bacteria with potential for biocontrol of various corn diseases, the surface-sterilized kernels of one unknown Italian corn cultivar produced fungus-free corn seedlings with roots endophytically infected byE. cloacae. This paper describes the microscopic nature ofE. cloacae RRC 101 with corn, and the in vitro control ofFusarium moniliforme and other fungi with this bacterium. Light and electron microscopy determined that this isolate ofE. cloacae was biologically associated with corn seedling roots, where it was distributed intercellularly within the cortex and stele. This is a first report of a strain of this bacterium as an endophytic symbiont of roots. Following a topical application ofE. cloacae to kernels, and upon germination this bacterium readily infected roots of two other corn cultivars. The bacterium was observed within the endosperm of germinating corn seedling, but germination was not affected. Further, the bacterium was isolated from leaves and stems of 3- to 6-week-old seedlings indicating that the above ground portions of corn were also colonized. There was no evidence of damage to cells of the root during a three to four week observation period. This bacterium was antagonistic to several isolates of the corn pathogenFusarium moniliforme, and to two other species of fungi, all of which produce mycotoxins on corn.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01103471
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  • 12
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    The phytotoxicity of selected mycotoxins on mature, germinatingZea mays embryos (1995)
    Springer
    Mycopathologia 132 (1995), S. 173-183 
    Details
    ISSN: 1573-0832
    Keywords: Deoxynivalenol ; Embryo ; Mature ; Ochratoxin ; Plantlet ; Zearalenone ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Mature maize (Zea mays) embryos were exposed to 5, 10 and 25 µg ml−1 of deoxynivalenol (DON), zearalenone (ZEA), ochratoxin A (OA) and a mixture of zearalenone and deoxynivalenol (ZEA/DON) for 9 days. DON and the ZEA/DON combination were consistently more inhibitory of the measured parameters than either ZEA or OA. Based on the predicted additive values, it would appear that, in combination, ZEA and DON act synergistically to inhibit root and shoot growth. For ZEA alone, a concentration of 5 µg ml−1 ZEA was generally inhibitory of root and shoot elongation and fresh mass accumulation, while at 10 and 25 µg ml−1, this toxin had a stimulatory effect on these parameters. For OA, the measured effects on root and shoot growth at 5 and 25 µg ml−1 were stimulatory, while at 10 µg ml−1 OA, an inhibitory effect was observed. For all toxins, inhibitory/stimulatory effects were generally more marked for root parameters than for shoot elongation or mass.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01103984
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  • 13
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    Orthophosphate solubility in waters of different ionic composition (1995)
    Springer
    Nutrient cycling in agroecosystems 44 (1995), S. 73-78 
    Details
    ISSN: 1573-0867
    Keywords: P precipitation ; precipitation kinetics ; P solubility diagram ; pH ; octacalcium phosphate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Orthophosphate (OP) is a major component of irrigation and nutrient solutions. Since OP precipitates may clog drippers, and deviations from intended OP concentrations may adversely affect plant development and yield, an understanding of the mechanisms controlling OP solubility in solutions of various ionic compositions, is essential. The objectives of this study were (i) to suggest guidelines for permitted OP additions to waters of various ionic compositions, so as to avoid OP crystallization and (ii) to predict the decrease in OP concentration as a function of time in supersaturated solutions. Five freshwater sources, used for irrigation in Israel, and representing extremes of pH and of Ca, HCO3 and SO4 concentrations, were tested. Solutions of three different initial OP concentrations (10, 30 and 90 mg Pl−1) and two pH values were prepared in 21 plastic bottles and kept in a dark room at 27 °C. Solution samples were withdrawn from the bottles at predetermined times, filtered and analysed for pH and total OP, Ca and HCO3 concentrations. In all the studied waters and for all initial OP levels the OP concentration (Cp) declined with time. The rate of decrease in Cp was proportional to the difference between the observed and equilibrium Cp values, with a specific rate constant for each water.The pH and the Ca2+ and HCO 3 − activities in solution were influenced by the initial Cp. The equilibrium Cp in all treatments was found to be controlled by octacalcium phosphate (OCP). Available chemical equilibria models allow to calculate the maximum level of OP that can be added to various waters before OCP precipitates, based on water pH and Ca, HCO3 and SO 4 2− concentrations.
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    URL: http://dx.doi.org/10.1007/BF00750694
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  • 14
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    Phosphorus sorption by three cultivated savanna alfisols as influenced by pH (1995)
    Springer
    Nutrient cycling in agroecosystems 44 (1995), S. 107-112 
    Details
    ISSN: 1573-0867
    Keywords: exchangeable Al ; exchangeable Ca ; ion pairs ; P sorption ; pH ; precipitation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract An earlier study of phosphate sorption by some savanna soils from Nigeria suggested that increased P sorption when pH was raised might be due to precipitation of exchangeable Al as amorphous polymeric Al species with increased sorption sites. But these savanna soils have Ca as the dominant cation in their exchange sites, and low exchangeable Al. The objective of this study was to determine the role played by Ca in pH-induced P sorption of three savanna soils under continuous cultivation. Phosphorus sorption increased when pH was raised from 4.5 to 7.0. Similarly, Ca retention increased with increasing pH. Regression of P sorption on Ca retention indicated a significant linear relationship in the three soils. Three possible mechanisms were proposed to explain the increasing P sorption with increasing pH: precipitation of Ca-phosphates, Ca-induced P sorption or co-adsorption of Ca and H2PO 4 − or HPO 4 2− as ion pairs or complexes. Available evidence suggests that all three mechanisms can operate together to enhance P retention as pH increases. The paper proposes that increased P sorption by savanna soils when pH is raised is likely to be related to the chemistry and retention of Ca rather than to hydrolytic reactions of Al.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00750799
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  • 15
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    A modified urea based NP fertilizer: urea-TSP-MAP combinations (1995)
    Springer
    Nutrient cycling in agroecosystems 45 (1995), S. 217-220 
    Details
    ISSN: 1573-0867
    Keywords: ammonia volatilization ; monoammonium phosphate ; pH ; urea triple superphosphate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Applying urea with acidic phosphate fertlizer increases urea fertilizer efficiency by reducing ammonia volatilization and toxicity to crop from urea hydrolysis. However, urea and triple superphosphate (TSP) are not recommended to be cogranulated because blends might become wet and sticky. Monoammonium phosphate (MAP) is a less acidic P source than TSP, but is compatible with urea. The objective of this study was to evaluate compound NP fertilizer products made from MAP and TSP combinations as P sources with urea. Fertilizer mixtures were pelletized from commercial urea, TSP and MAP with different N:P2O5 ratios and MAP/TSP combinations. Moisture changes during storage, pH of fertilizer solutions, and ammonia volatilization from surface applied fertilizer pellets were measured. Using MAP with TSP in urea-P mixtures reduced moisture increases during storage. Increasing MAP in urea-TSP-MAP combinations increased fertilizer solution pH by over 1 unit as the MAP/TSP-P2O5 ratio increased from 0/100 to 100/0. Adding MAP as 50% of P in urea-MAP-TSP mixtures at 3:1 and 1.5: (N:P2O5) ratios reduced ammonia loss from urea 50% to 60% compared to urea alone; and ammonia loss was similar to that of urea-TSP combinations. A urea-TSP-MAP fertilizer combination could make efficient use of urea-N by crops by reducing ammonia loss from urea hydrolysis.
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    URL: http://dx.doi.org/10.1007/BF00748592
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  • 16
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    Leaf litter processing and exoenzyme production on leaves in streams of different pH (1995)
    Springer
    Oecologia 102 (1995), S. 460-466 
    Details
    ISSN: 1432-1939
    Keywords: Detrital processing ; Exoenzymes ; ATP ; pH
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We examined microbial colonization, exoenzyme activity, and processing of leaves of yellow poplar (Liriodendron tulipifera), red maple (Acer rubrum), and white oak (Quercus alba) in three streams on the Allegheny Plateau of West Virginia, United States. Leaf packs were placed in streams that varied in their underlying bedrock geology, and therefore in their sensitivity to the high level of acidic precipitation that occurs in this region. The mean pH of the streams was 4.3 in the South Fork of Red Run (SFR), 6.2 in Wilson Hollow Run (WHR), and 7.7 in the North Fork of Hickman Slide Run (HSR). Through time, the patterns of microbial biomass and exoenzyme activity were generally similar among leaf species, but the magnitude of microbial biomass and exoenzyme activity differed among leaf species. Pectinase activity was greatest in HSR, the most alkaline stream, whereas the activity of exocellulase and xylanase was greatest in WHR and SFR, the intermediate and acidic streams. This variation in the activity of different exoenzymes was consistent with published pH optima for these exoenzymes. Variation in processing rates, both among leaf species and among streams, seems to be related to the level of microbial exoenzyme activity on the leaf detritus.
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    URL: http://dx.doi.org/10.1007/BF00341358
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  • 17
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    Deleterious effect of minimal enzymatic treatments on the development of isolated maize embryo sacs in culture (1995)
    Springer
    Sexual plant reproduction 8 (1995), S. 313-317 
    Details
    ISSN: 1432-2145
    Keywords: Embryo sac ; Zea mays ; Enzymatic isolation ; Zygotic embryogenesis ; Microinjection
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The long-term viability of isolated embryo sacs was studied in maize. Fertilised embryo sacs were digested in order to remove most of the nucellus cells present on their surfaces and then transferred to culture. Experiments on 161 embryo sacs showed that isolation treatments using even minimal enzymatic digestion affected the further development of the embryo sacs. Few embryo sacs survived in culture and those produced only abnormal embryos; they produced no plants. We concluded that embryo sacs isolated through enzymatic digestion may offer limited prospects for long-term studies where normal embryogenic development is required. Alternative strategies are discussed for maize.
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    URL: http://dx.doi.org/10.1007/BF00229389
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    Effects of calcium, magnesium, potassium and boron on sperm cells isolated from pollen of Zea mays L. (1995)
    Springer
    Sexual plant reproduction 8 (1995), S. 113-122 
    Details
    ISSN: 1432-2145
    Keywords: Zea mays ; Calcium ; Cell integrity ; Cell viability ; Sperm cell
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Our previous studies showed that Brewbaker and Kwack salts, which have been widely used in pollen germination and sperm isolation, are not appropriate for the maintenance of isolated maize (Zea mays L.) sperm cells. In the present study, we have characterized the effects of each BKS component salt on the integrity of isolated sperm cells using hemacytometry. At 0.01 and 0.1 mM, there were no differences in cell number between control and any salt-treated cells except a 22% decrease with 0.1 mM MgSO4 at 48 h. At the 1 mM level, cell number decreased with time in the presence of Ca(NO3)2 and MgSO4, with loss of integrity of most cells at 48 h, while KNO3 and H3BO3 had little or no effect. Further characterization of calcium-induced reduction in cell integrity using flow cytometry showed that depletion of possible residual free calcium by addition of EGTA to the suspension medium improved cell longevity and viability. Exposure of isolated sperm cells to 1 mM calcium had no effect on cell integrity and viability in 5 h; however, only 12% of cells remained intact at 24 h. The reduction in cell integrity was hastened when cells were pretreated with the calcium ionophore A23187 prior to exposure to 1 mM calcium, with a 54% reduction in cell number at 1 h and complete cell lysis at 24 h. However, depletion of cytosolic free calcium by pretreatment of cells with the calcium ionophore followed by resuspension in the presence of EGTA resulted in rapid reduction of cell integrity as well. These results collectively suggest that maize sperm cells are sensitive to exogenous free calcium; however, a certain level of cytosolic free calcium is necessary for maintenance of integrity. Mechanisms of calcium-induced reduction in cell integrity are discussed along with possible roles of the sensitivity of sperm cells to calcium in fertilization.
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    URL: http://dx.doi.org/10.1007/BF00230898
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    Effect of carbon source and pH of the growth medium on spore germination in Phycomyces blakesleeanus (1995)
    Springer
    Archives of microbiology 164 (1995), S. 231-234 
    Details
    ISSN: 1432-072X
    Keywords: Key words Spore activation ; Phycomyces ; Carbon source ; pH
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Phycomyces blakesleeanus sporangiospores responded differently to activation by physical and chemical stimuli. Spores that were physically (heat shock) activated or chemically (ammonium acetate) activated germinated and grew at pH 4.5 with the hexoses glucose, fructose, galactose, and N-acetylglucosamine, and with glycerol and amino acids. Under these conditions, physically activated spores showed a lower, although significant growth with the hexoses fructose, galactose, N-acetylglucosamine and with glycerol. On the other hand, physically activated spores incubated at alkaline pH (pH 7.3) required glucose to germinate; a requirement not observed with chemically activated spores, which showed significant growth in the other hexoses tested. Both physically and chemically activated spores incubated at pH 7.3 were unable to germinate and grow with amino acids and glycerol. These results suggest that there are different targets for activation of the spores by physical and chemical treatments. The levels of the fermentative enzymes alcohol dehydrogenase and lactate dehydrogenase and of the oxidative enzyme NAD+-isocitrate dehydrogenase were higher in cells grown at pH 4.5 in medium containing glucose; however, alcohol dehydrogenase and lactate dehydrogenase appear not to be affected by a change in the pH of the growth medium.
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    URL: http://dx.doi.org/10.1007/s002030050259
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  • 20
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    Cations adsorbed to soil organic matter — A regulatory factor for the release of organic carbon and hydrogen ions from soils to waters (1995)
    Springer
    Water, air & soil pollution 85 (1995), S. 1095-1100 
    Details
    ISSN: 1573-2932
    Keywords: acidity ; aluminium ; metal cations ; pH ; soil organic carbon
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Surface waters in northern forest ecosystems receive a substantial amount of drainage water from superficial soil horizons enriched in organic matter (SOM). Chemical reactions in the interface between the soil solution andf organic colloides will therefore affect the surface water chemistry. The mobilization of total organic carbon (TOC) and pH was studied as a function of amounts of organically adsorbed Na, Ca and Al in two O and one A horizon, which differed in the likelihood of contributing to the chemistry in runoff, in a forested watershed in northern Sweden. The samples were hydrogen ion saturated, washed and titrated with NaOH, Ca(OH)2 and Al(OH)3 in a constant ionic medium of 0.01 M NaCl in order to give rise to a population of manipulated samples differing in the composition of adsorbed cations. The highly humified SOM accumulated in the Oh and Ah horizons of a Gleysol close to the draining stream was stabilized by flocculating Al (95% of adsorbed metal cations), which resulted in a low release of TOC. These horizons showed a high potential of organic carbon solubility when Al was changed for di- or monovalent cations. Calculations suggested that the release of TOC would increase more than ten times if Al was exchanged for Ca upon liming to pH 6.0. The pH values of all horizons were shown to be determined mainly by the composition of adsorbed mono-,di- and trivalent cations.
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    URL: http://dx.doi.org/10.1007/BF00477127
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  • 21
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    Snowpack quality as an indicator of air pollution in Finnish Lapland and the Kola Peninsula, NW Russia (1995)
    Springer
    Water, air & soil pollution 85 (1995), S. 2185-2190 
    Details
    ISSN: 1573-2932
    Keywords: Cu ; Cu-Ni smelters ; Kola Peninsula ; Lapland ; Ni ; pH ; S ; snowpack
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Bulk snow samples were collected from the snowpack in open areas along two sampling lines running to the west from the Cu-Ni smelters at Nikel and Monchegorsk, NW Russia, during 1991–1993. The aim of the study was to estimate the area affected by sulphur and heavy metal deposition from the smelters. Snowpack quality was used as an indicator of deposition during winter time. The total sulphur, copper and nickel concentrations in the snowpack decreased significantly (p〈0.001) with increasing distance from the smelters along the sampling line running directly to the west from Monchegorsk. The deposition pattern was similar each winter during 1991–1993. The pH values did not correlate with the corresponding sulphur concentrations, and there was no decreasing pH gradient in the snowpack on moving towards Monchegorsk. The effects of sulphur emissions from Monchegorsk on snowpack chemistry were not detectable on the Finnish side of the border. The 3-year mean of the total sulphur concentration was 0.27 mg/kg, and of the pH values 4.92, along the sampling line running to the west of Monchegorsk. The total sulphur concentrations near the smelters (〈 20 km) varied between 0.37 and 0.95 mg/kg. The effect of the Cu-Ni smelters at Nikel on snowpack quality was not detectable in northern Finnish Lapland. The 3-year mean for total sulphur was 0.20 mg/kg and for pH 4.96 along the sampling line running to the west of Nikel.
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    URL: http://dx.doi.org/10.1007/BF01186158
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    The toxic mixing zone of neutral and acidic river water: Acute aluminium toxicity in brown trout (Salmo trutta L.) (1995)
    Springer
    Water, air & soil pollution 85 (1995), S. 341-346 
    Details
    ISSN: 1573-2932
    Keywords: aluminium toxicity ; non-equilibrium chemistry ; pH ; stress ; apoptosis ; necrosis ; trout
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Mixing of acid river water containing aluminium (pH 5.1, Al 345 μg.l−1) with neutral water of a lake (pH 7.0, Al 73 μg.l−1) resulted in water (pH 6.4, Al 245 μg.l−1) with a pH (6.4) and Al concentration (245 μg.l−1) expected to have low toxicity to fish on the basis of current Al toxicity models. However, under semi-field conditions the freshly mixed water (a few sec. after mixing) proved to be highly toxic to brown trout. The fish were exposed to the water at different places along a 30 m channel. At the beginning of the channel acid and neutral water were continuously mixed; the mixed water left the channel after 340 sec. The cells of the gills showed a highly increased rate of cell death by apoptosis and necrosis. Intercellular spaces were enlarged, and many leucocytes penetrated in these spaces. Mucus release was stimulated to depletion. Plasma chloride levels were hardly affected. There was a clear gradient in the deleterious effects on the fish along the channel. The fish at the beginning of the channel (about 12 sec. after mixing of the water), were severely affected, whereas the fish kept at the end of the channel (340 sec. after mixing) were only mildly affected. In the natural situation fish will relatively quickly pass through a mixing zone. In our study we therefore focused on the effects on fish after a 60 min exposure to a mixing zone (5 sec after mixing), with subsequent recovery in a region downstream of the confluence and in neutral water with low Al. The recovery in the downstream area (at the end of the channel, i.e. 5 min after mixing) was clearly hampered when compared to the recovery in neutral water with low aluminium. Thus, a short exposure to the toxic mixing zone followed by a stay in water downstream of this zone, as may occur in nature, is detrimental to migrating trout. We conclude that freshly mixed acid and neutral water contain toxic components during the first seconds to minutes after mixing, that can not be explained by current models on aluminium toxicity.
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    URL: http://dx.doi.org/10.1007/BF00476852
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    Soil solution chemistry and element budgets of three Scots pine ecosystems along a deposition gradient in north-eastern Germany (1995)
    Springer
    Water, air & soil pollution 85 (1995), S. 1197-1202 
    Details
    ISSN: 1573-2932
    Keywords: Scots pine ; Pinus sylvestris ; deposition ; element budget ; soil solution ; soil chemistry ; alkaline dust ; pH ; acidification ; sulfur release
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Since 1993 we are studying three Scots pine ecosystems along a deposition gradient in north-eastern Germany (formerly GDR). Dramatic reductions of pollutant emissions are reported for the period since 1989/90. S-deposition is high at the sites Roesa and Taura (25 kg S ha−1yr−1) compared to Neuglobsow. Inputs of basic cations, especially Ca, by alkaline dust immissions decrease in the order Roesa 〉 Taura 〉 Neuglobsow. The soil solution data show high concentrations of Ca and SO4 at Roesa decreasing drastically along the deposition gradient. The elevated pH values reflect the impact of alkaline dust deposition particularly in the organic surface layer at Roesa. The site Taura received less base cation deposition and is marked by the lowest pH values throughout the soil profile combined with increased Al concentrations in the solution of the mineral soil. Thus, the composition of the soil solutions clearly reflects the different deposition regimes of the past. The element budgets show that large amounts of base cations, sulfur, and, at Taura, also aluminum are actually released from the soils that were previously stored.
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    URL: http://dx.doi.org/10.1007/BF00477144
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    Deposition around a coal-fired power station during a wintertime precipitation event (1995)
    Springer
    Water, air & soil pollution 85 (1995), S. 2125-2130 
    Details
    ISSN: 1573-2932
    Keywords: wet deposition ; sulphate ; pH ; snowfall ; Doppler weather radar ; short-range deposition modelling
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract The contribution to local wet deposition of emissions from a coal-fired power station at Inkoo on the south coast of Finland has been investigated during a wintertime precipitation event. Making use of intensive radiosonde and weather radar observations of meteorological factors, concentrations of sulphur in deposition due to plume washout were predicted by a short-range deposition model. The model used the scavenging coefficient to parametrize the wet removal of pollutants, and it took into account the wind drift of falling precipitation particles within the plume. The model predictions were then compared with the chemical analysis results from snowfall samples collected within 10 km of the power station during the experiment. The experiment was performed ahead of a deeply-occluded front during a period with strong advection of long-range transported pollutants. No reliable sign of the influence of the power station on the sulphate deposition could be identified. On the other hand, the deviations of acidity from the mean pH-value of 4.1 were concentrated in one sector near the expected area of deposited plume pollutants. If local emissions were responsible for these deviations, the explanation may lie in a slightly incorrectly estimated plume direction or the effects of alkaline fly ash. Nevertheless, definite conclusions cannot be drawn, because only a few collectors happened to be sited in the modelled sector of plume washout and none in its maximum area.
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    URL: http://dx.doi.org/10.1007/BF01186148
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    A Zea mays GTP-binding protein of the ARF family complements an Escherichia coli mutant with a temperature-sensitive malonyl-coenzyme A:acyl carrier protein transacylase (1995)
    Springer
    Plant molecular biology 27 (1995), S. 629-633 
    Details
    ISSN: 1573-5028
    Keywords: GTP binding ; ADP ribosylation ; Zea mays ; Escherichia coli ; fatty acid biosynthesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In an attempt to isolate a plant malonyl-coenzyme A:acyl carrier protein transacylase cDNA clone, by direct genetic selection in an Escherichia coli fabD mutant (LA2-89) with a maize cDNA expression library, a Zea mays cDNA clone encoding a GTP-binding protein of the ARF family was isolated. Complementation of a mutation affecting bacterial membrane lipid biosynthesis by a plant ARF protein, could indicate the existence of as yet unidentified bacterial equivalents of this ubiquitous eucaryotic GTP-binding protein.
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    URL: http://dx.doi.org/10.1007/BF00019329
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    The involvement of Opaque 2 on β-prolamin gene regulation in maize and Coix suggests a more general role for this transcriptional activator (1995)
    Springer
    Plant molecular biology 27 (1995), S. 1015-1029 
    Details
    ISSN: 1573-5028
    Keywords: β-prolamin ; Coix lacryma-jobi ; different O2-binding sites ; Opaque 2 ; transcriptional regulation ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The maize opaque 2 (o2) mutation is known to have numerous pleiotropic effects. Some polypeptides have their expression depressed while others are enhanced. The best characterized effects of the o2 mutation are those exerted on endosperm genes encoding the storage protein class of the 22 kDa α-zeins and the ribosome inactivating protein b-32. The Opaque 2 (O2) locus encodes a basic domain-leucine zipper DNA-binding factor, O2, which transcriptionally regulates these genes. In the maize-related grass Coix lacryma-jobi, an O2-homologous protein regulates the 25 kDa α-coixin gene family. We show in this paper that O2 transcriptionally regulates the structurally and developmentally different class of the β-prolamins. A new O2-binding box was identified in β-prolamin genes from maize and Coix that, together with the boxes previously identified in other endosperm expressed genes, forms a curious collection of O2 cis elements. This may have regulatory implications on the role of O2 in the mechanism that controls coordinated gene expression in the developing endosperm. Considering that the O2 locus controls at least three distinct classes of genes in maize endosperm, we propose that the O2 protein may play a more general role in maize endosperm development than previously conceived.
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    URL: http://dx.doi.org/10.1007/BF00037028
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    Molecular cloning, characterization and expression of an elongation factor 1α gene in maize (1995)
    Springer
    Plant molecular biology 29 (1995), S. 611-615 
    Details
    ISSN: 1573-5028
    Keywords: elongation factor 1α ; EF-1α ; Zea mays ; cDNA sequence ; gene
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A cDNA (zmEF1A) and the corresponding genomic clone (zmgEF1A) of a member of the gene family encoding the α subunit of translation elongation factor 1 (EF-1α) have been isolated from maize. The deduced amino acid sequence is 447 residues long interrupted by one intron. Southern blot analysis reveals that the cloned EF-1α gene is one member out of a family consisting of at least six genes. As shown by northern hybridizations in leaves the mRNA level increases at low temperature whereas time-course experiments over 24 h at 5°C show that in roots the overall mRNA level of EF-1α is transiently decreased. These results indicate that the expression of EF-1α is differently regulated in leaves and roots under cold stress.
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    URL: http://dx.doi.org/10.1007/BF00020988
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  • 28
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    The maize GapC4 promoter confers anaerobic reporter gene expression and shows homology to the maize anthocyanin regulatory locus C1 (1995)
    Springer
    Plant molecular biology 29 (1995), S. 1293-1298 
    Details
    ISSN: 1573-5028
    Keywords: anaerobiosis ; BMS cells ; glyceraldehyde-3-phosphate dehydrogenase ; transient gene expression ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The cytosolic glyceraldehyde-3-phosphate dehydrogenase (GapC) gene family of maize is differentially expressed in response to anaerobic stress. While GapC1 and GapC2 are downregulated, GapC3 and GapC4 are anaerobically induced. We have sequenced and analyzed a 3073 bp promoter fragment of GapC4. The promoter confers anaerobic induction of a reporter gene construct in a transient gene expression system in maize. Deletion analysis of the GapC4 promoter revealed a 270 bp long DNA region required for anaerobic induction. This region contains sequence motifs resembling the cis-acting sequences of the anaerobically induced maize Adh1 and Adh2 genes. Furthermore, the 3073 bp GapC4 promoter fragment displays homology to long terminal repeats of maize retrotransposons and to the 3′ region of the maize anthocyanin regulatory locus C1.
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    URL: http://dx.doi.org/10.1007/BF00020469
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    Molecular cloning and characterization of six cDNAs expressed during glucose starvation in excised maize (Zea mays L.) root tips (1995)
    Springer
    Plant molecular biology 28 (1995), S. 473-485 
    Details
    ISSN: 1573-5028
    Keywords: carbon catabolite repression ; cDNA ; gene expression ; stress-induced genes ; glucose-starvation ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In order to isolate glucose-starvation-related cDNAs in maize (Zea mays L.) root tips, a cDNA library was constructed with poly(A)+ mRNA from 24 h starved root tips. After differential screening of the library, we isolated six different cDNAs (named pZSS2 and pZSS7) which were expressed during glucose starvation. Time course analysis revealed that maximum expression of five of these genes occurs 30 h after the onset of the starvation treatment. On the contrary, the expression of mRNAs corresponding to pZSS4 was maximal at an early stage of starvation and then dramatically decreased. The expression of this gene did not seem to be specific for glucose starvation. The pattern of induction of the genes corresponding to pZSS2, pZSS3, pZSS5, pZSS6 and pZSS7 revealed that non-metabolizable sugars such as L-glucose and mannitol induce mRNA transcription similarly to glucose starvation. When D-glucose or any other metabolizable sugar was supplied, the level of transcripts was reduced. Nucleotide sequence analyses of the six cDNAs allowed identification of five of them by comparison with sequence data bases. The protein encoded by clone pZSS2 is analogous to a wound-induced protein from barley. Clones pZSS4 to pZSS7 encode, respectively, a transmembrane protein, a cysteine protease, a metallothionein-like protein and a chymotrypsin/subtilisin-like protease inhibitor. Clone pZSS3 shares no significant homology with any known sequence.
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    Intron-dependent transient expression of the maize GapA1 gene (1995)
    Springer
    Plant molecular biology 28 (1995), S. 667-676 
    Details
    ISSN: 1573-5028
    Keywords: gene expression ; promoter ; glyceraldehyde-3-phosphate dehydrogenase ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Transient expression experiments show that the maize GapA1 promoter exhibits a requirement for sequences contained within intron 1 and surrounding exon border regions for expression in maize Black Mexican Sweet cells. Maize GapA1-promoter constructs lacking intron 1 are inactive. Intron 1 and its exon border sequences, when reintroduced into constructs lacking introns, restore gene activity whereas intron 2 and its exon borders to not. The minimal promoter so defined encompasses roughly 250 bp upstream of the in vivo transcription start and appears also to include intron 1. An octameric sequence was identified in intron 1 of maize GapA1 which is similar to sequence motifs found in other maize introns known to increase transient expression. Partial restoration of gene expression in GapA1 constructs lacking intron 1 was achieved through insertion of the identified octameric sequence.
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    URL: http://dx.doi.org/10.1007/BF00021192
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    PCR-generated cDNA library of transition-stage maize embryos: cloning and expression of calmodulin genes during early embryogenesis (1995)
    Springer
    Plant molecular biology 27 (1995), S. 105-113 
    Details
    ISSN: 1573-5028
    Keywords: calmodulin ; cDNA library ; embryogenesis ; PCR ; transition stage ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract One hundred maize zygotic embryos microdissected at the transition stage were used to construct a cDNA library after non-selective PCR (NS-PCR) amplification of whole cDNA populations. The library contains 2.3 × 105 recombinants and two different calmodulin cDNAs were cloned using a heterologous probe from petunia. Calmodulin expression was confirmed throughout maize embryogenesis at the mRNA, amplified cDNA and protein levels. Sequence analysis suggests a maize origin for both clones and negligible nucleotide changes linked to PCR. This library is the first described for early plant embryos and represents a breakthrough to isolate genes involved in embryo differentiation.
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    URL: http://dx.doi.org/10.1007/BF00019182
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    Evidence for the thiamine biosynthetic pathway in higher-plant plastids and its developmental regulation (1995)
    Springer
    Plant molecular biology 29 (1995), S. 809-821 
    Details
    ISSN: 1573-5028
    Keywords: Zea mays ; thiamine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Thiamine or vitamin B-1, is an essential constituent of all cells since it is a cofactor for two enzyme complexes involved in the citric acid cycle, pyruvate dehydrogenase and α-ketoglutarate dehydrogenase. Thiamine is synthesized by plants, but it is a dietary requirement for humans and other animals. The biosynthetic pathway for thiamine in plants has not been well characterized and none of the enzymes involved have been isolated. Here we report the cloning and characterization of two cDNAs representing members of the maize thi1 gene family encoding an enzyme of the thiamine biosynthetic pathway. This assignment was made based on sequence homology to a yeast thiamine biosynthetic gene and by functional complementation of a yeast strain in which the endogenous gene was inactivated. Using immunoblot analysis, the thi1 gene product was found to be located in a plastid membrane fraction. RNA gel blot analysis of various tissues and developmental stages indicated thi1 expression was differentially regulated in a manner consistent with what is known about thiamine synthesis in plants. This is the first report of cDNAs encoding proteins involved in thiamine biosynthesis for any plant species.
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    URL: http://dx.doi.org/10.1007/BF00041170
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    Manipulating cytoplasmic pH under anoxia: A critical test of the role of pH in the switch from aerobic to anaerobic metabolism (1995)
    Springer
    Planta 195 (1995), S. 324-330 
    Details
    ISSN: 1432-2048
    Keywords: Anoxia ; Biochemical pH-stat ; Cytoplasmic pH ; Ethanol production ; Pyruvate decarboxylase ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Ethanol production by maize (Zea mays L.) root tips, measured by an enzymic assay of the suspending medium, was correlated with changes in the cytoplasmic pH, determined by in-vivo 31P nuclear magnetic resonance (NMR) spectroscopy, following the onset of anoxia. Strong evidence for the role of the cytoplasmic pH in triggering the switch to ethanol production under anoxia was obtained by: (i) varying the pH of the suspending medium between pH 4 and pH 10; and (ii) using the permeant weak base methylamine to combat the acidification of the cytoplasm induced by the anoxic conditions. Experimentally, it proved to be much easier to manipulate the cytoplasmic pH under anoxia after the pH had stabilised, rather than during the initial rapid acidification that occurred following the onset of anoxia, and in the presence of methylamine, it was possible to impose a normal aerobic cytoplasmic pH value on tissue that was metabolising anaerobically. By this means it was possible to demonstrate the reversibility of the pH effect on ethanol production under anoxia and thus to provide good evidence in support of the biochemical pH-stat model of the anoxic response. The NMR measurement of the cytoplasmic pH in the presence of methylamine was achieved by using a manganese pretreatment technique to eliminate interference between the cytoplasmic and vacuolar Pi signals, and it seems likely that the experimental approach used here will have further applications in studies of the metabolic response to anoxia.
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    URL: http://dx.doi.org/10.1007/BF00202588
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    Protons and calcium modulate SV-type channels in the vacuolar-lysosomal compartment — channel interaction with calmodulin inhibitors (1995)
    Springer
    Planta 197 (1995), S. 655-671 
    Details
    ISSN: 1432-2048
    Keywords: Calcium ; Calmodulin antagonists ; pH ; SV-type channels (vacuole) ; Taproot, guard cells
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Slowly activating vacuolar (SV-type; Hedrich and Neher 1987, Nature 329: 833–835) ion channels provide the predominant membrane conductance of the vacuolar-lysosomal compartment of Vicia faba L. guard cells and sugar beet (Beta vulgaris L.) taproots. Applying the patch-clamp technique to isolated vacuoles of both tissues, the electrical and pharmacological properties of guard-cell SV-type currents were studied and compared to the sugar beet channel with regard to its modulation by cytoplasmic Ca2+ and pH. This outward rectifier of V. faba guard cells showed a half-maximum activation at 55–60 mV with an apparent gating charge equivalent of z ≈ 4. Studies on the single-channel and whole-vacuole level revealed an extremely high conductance of 280 pS for the guard-cell channels at a mean density of 0.37 μm-2 compared to taproots (120–140 pS at about 0.16 channels per μm2). Guard-cell SV-type channels are weakly selective for cations over anions and lack saturation at KC1 concentrations of up to 1 M. Since in the absence of physiological K+ concentrations, Ca2+ is the major permeable ion, relative changes in the amounts of the two ions might control the permeation process. In spite of their different origins and physiological functions, in guard cells and beet taproot cells, cytoplasmic Ca2+ and protons, both considered as candidates for intracellular signalling in plants, modulate the voltage dependence of SV-type channels. While the two effectors do not alter the single-channel conductance, they strongly interact with the voltage sensor. The calmodulin (CaM) antagonists N-(6-aminohexyl)-5-chloro-l-naphthalenesulfonamide hydrochloride (W-7), trifluoperazine (TFP) and calmidazolium hydrochloride (R 24571) effectively blocked the channel in an antagonist-specific manner. In agreement with the properties of a Ca2+-permeable channel, CaM could be involved in the modulation of the activation threshold of the SV-type channel. We therefore conclude that guard-cell SV-type channels, which might be responsible for the release of K+, Cl- and to a smaller extent Ca2+ during stomatal closure, could serve as an intracellular sensor for changes in cytosolic calcium (calcium-CaM) and pH.
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    ATP, pH and Mg2+ modulate a cation current in Beta vulgaris vacuoles: A possible shunt conductance for the vacuolar H+-ATPase (1995)
    Springer
    The journal of membrane biology 145 (1995), S. 75-86 
    Details
    ISSN: 1432-1424
    Keywords: Amino acid transport ; ATP regulation ; Beta ; Mg2+ ; pH
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Macroscopic instantaneous and time-dependent currents have been measured in the vacuolar membrane of Beta vulgaris using a patch clamp configuration analogous to whole cell mode. At low cytosolic Ca2+ and in the absence of Mg2+, only an instantaneous current was observed. This current is carried predominantly by cations (PK∶PCl 7∶1, pna∶pcl 4∶1 and arginine is also conducted). The instantaneous current can be activated by ATP4− (e.g., ATP-activated mean K+ current density was −20 mA.m−2 at a membrane voltage of −20 mV) and by increasing cytosolic pH and Mg2+ (raising Mg2+ from 0 to 0.4 mm induced a mean current density increase of −7 mA.m−2 at −20 mV). Such current can be activated by simultaneous addition of putative in vivo concentrations of ATP4−/MgATP/Mg free 2+ (in the presence of bafilomycin to inhibit the vacuolar ATPase) and further modulated by cytosolic pH. With vacuolar K+ concentration greater than that of the cytosol, activation of the instantaneous current would mediate vacuolar K+ release over the range of physiological membrane voltage. It is argued that the ATP4−-activated current, in addition to acting as a K+ mobilization pathway, could provide a counter-ion (shunt) conductance, allowing the two electrogenic H+ pumps which reside in the vacuolar membrane to acidify the vacuolar lumen. A separate time-dependent current, which was not observed at low Ca2+ concentrations (less than 500 nm) could also be elicited by addition of Mg2+ at the cytoplasmic membrane face. This current was stimulated by increasing cytoplasmic pH.
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    The pH-sensitivity of transepithelial K+ transport in vestibular dark cells (1995)
    Springer
    The journal of membrane biology 147 (1995), S. 255-262 
    Details
    ISSN: 1432-1424
    Keywords: Labyrinth ; Slowly activating K+ channel ; IsK channel ; MinK channel ; pH
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The pH-sensitivity of transepithelial K+ transport was studied in vitro in isolated vestibular dark cell epithelium from the gerbil ampulla. The cytosolic pH (pH iwas measured microfluorometrically with the pH-sensitive dye 2′,7′-bicarboxyethyl-5(6)-carboxyfluorescein (BCECF) and the equivalent short-circuit current (I sc), which is a measure for transepithelial K+ secretion, was calculated from measurements of the transepithelial voltage (V t)and the transepithelial resistance (R t) in a micro-Ussing chamber. All experiments were conducted in virtually HCO 3 − -free solutions. Under control conditions, pH iwas 7.01±0.04 (n=18), V twas 9.1±0.5 mV, R t16.7±0.09 Ωcm2, and I sc was 587±30 μA/cm2 (n=49). Addition of 20 mm propionate− caused a biphasic effect involving an initial acidification of pH i, increase in V tand I sc and decrease in R tand a subsequent alkalinization of pH i, decrease of V tand increase of R t. Removal of propionate− caused a transient effect involving an alkalinization of pH i, a decrease of V tand I sc and an increase in R t. pH iin the presence of propionate− exceeded pH iunder control conditions. Effects of propionate − on V t, R tand I sc were significantly larger when propionate− was applied to the basolateral side rather than to the apical side of the epithelium. The pH i-sensitivityof I sc between pH 6.8 and 7.5 was −1089 μA/(cm2 · pH-unit) suggesting that K+ secretion ceases at about pH i7.6. Acidification of the extracellular pH (pH o)caused an increase of V tand I sc and a decrease of R tmost likely due to acidification of pH i. Effects were significantly larger when the extracellular acidification was applied to the basolateral side rather than to the apical side of the epithelium. The pH osensitivity of I sc between pH 7.4 and 6.4 was −155 μA/(cm2 · pH unit). These results demonstrate that transepithelial K+ transport is sensitive to pH iand pH oand that vestibular dark cells contain propionate− uptake mechanism. Further, the data suggest that cytosolic acidification activates and that cytosolic alkalinization inactivates the slowly activating K+ channel (I sK)in the apical membrane. Whether the effect of pH ion the I sK channel is a direct or indirect effect remains to be determined.
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    pH- and voltage-dependent conductances in toad skin (1995)
    Springer
    The journal of membrane biology 148 (1995), S. 1-11 
    Details
    ISSN: 1432-1424
    Keywords: Toad skin ; pH ; Ion conductance ; Voltage dependence ; Chloride conductance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The present study focuses on two closely related topics on ion conductance in toad skins: (i) the interaction of apical protons with the apical voltage-dependent Cl−-activated channels of the mitochondriarich cells, and (ii) the description and characterization of a novel subject, a voltage-dependent H+-activated conductance. The Cl− conductance (G Cl) is activated by tissue hyperpolarization (which leads to apical membrane depolarization) and the presence of Cl− ions in the apical solution. Increasing apical proton concentration (from pH 8 to pH 4) impairs the process of activation of the Cl− conductive pathway, slowing the kinetics of I t activation and reducing the steady-stage values of G t and I t . This effect is markedly voltage-dependent since no effect is seen at V t =−100 mv and is fully present at −50 mV. The voltage-dependence of the pH effect suggests that the critical protonation sites of the apical Cl− channels are not freely exposed to the apical solution but dwell within the membrane electric field. An also coherent interpretation is that titration of apical proton binding sites affects the gating of the voltage-dependent Cl− channels, shifting the conductance-vs.-voltage curve to more negative clamping potentials. Tissue conductance in the absence of apical Cl− ions can be importantly affected by the pH of the apical solution (pH a ), the effect being markedly dependent on the clamping potential. Generally speaking, the effect of rising apical proton concentration can be conspicuous at negative clamping potentials, while at positive potentials changes in tissue conductance were never observed. For a clamping potential of −100 mV, a turning point somewhere between pH a =4 and pH a =3 was observed. Apical acidification to pH 4 has no effect upon tissue conductance while apical acidification to pH 3 leads to a marked, slow and reversible increase of tissue conductance. A striking similitude exists between the voltage-dependent Cl−-gated conductance and the voltage-dependent proton-gated conductance regarding: (i) slow time courses of activation and deactivation, (ii) requirement for a negative clamping potential and the presence of a specific ion species in the apical solution for activation to take place, (iv) instantaneous ohmic behavior, and (v) steady-state rectification. However, so far the results do not permit one to conclude definitely that the voltage-dependent Cl−-gated conductance and the voltage-dependent proton-gated conductance share a common pathway.
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    A voltage-dependent and pH-sensitive proton current in Rana esculenta oocytes (1995)
    Springer
    The journal of membrane biology 147 (1995), S. 207-215 
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    ISSN: 1432-1424
    Keywords: Rana esculenta oocytes ; H+ current ; pH ; Voltage clamp
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Voltage clamp technique was used to study macroscopic ionic currents in Rana esculenta oocytes. Depolarization steps led to the activation of a single type of outward current (I out) when contaminant potassium and calcium-dependent chloride currents were pharmacologically inhibited. The voltage threshold of I out activation was 10 mV and this current, which did not inactivate, presented a deactivation the time constant of 73±21 msec (n=26) corresponding to a membrane voltage of −60 mV. Its reversal potential (E rev) was dependent on the magnitude of the depolarization and also on pulse duration. These changes in E rev were thought to reflect intracellular ion depletion occurring during activation of the remaining outward current. Furthermore, the activation threshold of I out was clearly affected by modifications in extracellular and intracellular H+ concentrations. Indeed, intracellular alkalinization (evoked by external application of ammonium chloride) or extracellular acidification induced a rightward shift in the activation threshold while intracellular acidification (evoked by external application of sodium acetate) or extracellular alkalinization shifted this threshold toward a more negative value. Lastly, I out was dramatically reduced by divalent cations such as Cd2+, Ni2+ or Zn2+ and was strongly decreased by 4 Aminopyridine (4-AP), wellknown H+ current antagonists already described in many cell types. Therefore, it was suggested that the outward current was prominently carried by H+ ions, which may play a key role in the regulation of intracellular pH and subsequent pH dependent processes in Rana oocyte.
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    Transport and dynamics of molecules dissolved in maize root cortex membranes (1995)
    Springer
    The journal of membrane biology 143 (1995), S. 19-28 
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    ISSN: 1432-1424
    Keywords: Plant membrane ; Lipid domain ; Fluorescence photobleaching recovery ; Electron paramagnetic resonance ; Temperature stress ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Translational diffusion of a fluorescent sterol probe was measured in the plasma membranes of protoplasts isolated from cortical cells of the primary root of maize seedlings. The apparent lateral diffusion coefficient was typically observed to be nearly insensitive to temperature, while the mobile fraction increased with increasing temperature. These fluorescence photobleaching recovery (FPR) measurements were compared with the electron paramagnetic resonance (EPR) spectra of the methyl ester of 13-doxyl palmitic acid in membranes of corn root tissue in situ. The complex spectra observed with this probe were analyzed as weighted sums of simpler spectra of various order parameters and rotational correlation times. The reconstituted spectra calculated from the model show that EPR also detects a mobile (less ordered, fluid) fraction, distinguished by the order parameter S=0.1 to 0.2, which becomes more abundant as temperature increases and is qualitatively comparable to the mobile fraction determined by the FPR method. The observed results on the mobile fractions and the diffusion rates for translational (FPR) as well as rotational (EPR) motions are interpreted in terms of membrane organization, thus providing information on the population and structural patterns of the coexisting domains with a special emphasis on the response of the membrane to temperature changes.
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    Differential regulation of membrane potential and conductance via intra-and extracellular pH in fused proximal tubular cells of frog kidney (1995)
    Springer
    The journal of membrane biology 143 (1995), S. 123-134 
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    ISSN: 1432-1424
    Keywords: Membrane potential ; Conductances ; pH ; Acetate ; NH4C1
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Intracellular pH (pH i ), membrane potential (V m ) and membrane conductance (G m ) in fused proximal tubular cells of the frog kidney, were determined at three extracellular pH (pH o ) values, 7.5, 8.5 and 6.5. Imposed changes of pH o by ±1 pH unit induced parallel but smaller shifts of pH i . The alkaline milieu hyperpolarized the cells and increased G m , whereas the acid milieu depolarized and lowered G m . We subsequently introduced a weak acid and its conjugate base (acetic acid/acetate), or a weak base and its conjugate acid (NH3/NH 4 + ), at pH o 7.5, 8.5 and 6.5 to shift pH i -without altering pH o , or to shift pH i against imposed changes of pH o . From these experiments, we observed that under some circumstances V m varied with pH o but without G m or pH i changes, whereas under other circumstances changes of G m occurred during alterations of pH i while pH o and V m remained unaltered. At pH i ≈ 6.5 associated with V m ≈ −10 mV, G m dramatically increased to quasi-infinite values. This increase was not an artifact since G m returned to its control value following recovery to the control solution or in the presence of hyperosmotic solution. In conclusion, we demonstrate a differential regulation whereby V m and G m are controlled by pH o and pH i : pH o modulates mainly V m , and pH i modulates chiefly G m . Furthermore, at pH i ≈ 6.5 and V m ≈ −10 mV, our data reveal a large G m that tends towards infinite values in a reversible fashion.
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    The AQP2 water channel: Effect of vasopressin treatment, microtubule disruption, and distribution in neonatal rats (1995)
    Springer
    The journal of membrane biology 143 (1995), S. 165-175 
    Details
    ISSN: 1432-1424
    Keywords: Water channels ; Vasopressin ; Rat kidney ; Immunocytochemistry ; Microtubules ; Cell polarity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Aquaporin 2 is a collecting duct water channel that is located in apical vesicles and in the apical plasma membrane of collecting duct principal cells. It shares 42% identity with the proximal tubule/thin descending limb water channel, CHIP28. The present study was aimed at addressing three questions concerning the location and behavior of the AQP2 protein under different conditions. First, does the AQP2 channel relocate to the apical membrane after vasopressin treatment? Our results show that AQP2 is diffusely distributed in cytoplasmic vesicles in collecting duct principal cells of homozygous Brattleboro rats that lack vasopressin. In rats injected with exogenous vasopressin, however, AQP2 became concentrated in the apical plasma membrane of principal cells, as determined by immunofluorescence and immunogold electron microscopy. This behavior is consistent with the idea that AQP2 is the vasopressin-sensitive water channel. Second, is the cellular location of AQP2 modified by microtubule disruption? In normal rats, AQP2 has a mainly apical and subapical location in principal cells, but in colchicine-treated rats, it is distributed on vesicles that are scattered throughout the entire cytoplasm. This is consistent with the dependence on microtubules of apical protein targeting in many cell types, and explains the inhibitory effect of microtubule disruption on the hydroosmotic response to vasopressin in sensitive epithelia, including the collecting duct. Third, is AQP2 present in neonatal rat kidneys? We show that AQP2 is abundant in principal cells from neonatal rats at all days after birth. The detection of AQP2 in early neonatal kidneys indicates that a lack of this protein is not responsible for the relatively weak urinary concentrating response to vasopressin seen in neonatal rats.
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    Characterization of a chloride channel reconstituted from cardiac sarcoplasmic reticulum (1995)
    Springer
    The journal of membrane biology 147 (1995), S. 121-136 
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    ISSN: 1432-1424
    Keywords: Chloride channel ; Cardiac sarcoplasmic reticulum ; Planar lipid bilayer ; Ion selectivity ; Voltage ; Block ; pH
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract We have characterized a voltage-sensitive chloride channel from cardiac sarcoplasmic reticulum (SR) following reconstitution of porcine heart SR into planar lipid bilayers. In 250 mm KCl, the channel had a main conductance level of 130 pS and exhibited two substrates of 61 and 154 pS. The channel was very selective for Cl− over K+ or Na+ ( $$P_{{\text{K}}^{\text{ + }} } /P_{{\text{Cl}}^{\text{ - }} } = 0.012$$ and $$P_{{\text{Na}}^{\text{ + }} } /P_{{\text{Cl}}^{\text{ - }} } \sim 0.040$$ ). It was permeable to several anions and displayed the following sequence of anion permeability: SCN− 〉 I− 〉 NO 3 − ∼ Br− 〉 Cl− 〉 f− 〉 HCOO−. Single-channel conductance saturated with increasing Cl− concentrations (K m= 900 mm and γmax = 488 pS). Channel activity was voltage dependent, with an open probability ranging from ∼1.0 around 0 mV to ∼0.5 at +80 mV. From −20 to +80 mV, channel gating was time-independent. However, at voltages below −40 mV the channel entered a long-lasting closed state. Mean open times varied with voltage, from ∼340 msec at −20 mV to ∼6 msec at +80 mV, whereas closed times were unaffected. The channel was not Ca2+-dependent. Channel activity was blocked by disulfonic stilbenes, arylaminobenzoates, zinc, and cadmium. Single-channel conductance was sensitive to trans pH, ranging from ∼190 pS at pH 5.5 to ∼60 pS at pH 9.0. These characteristics are different from those previously described for Cl− channels from skeletal or cardiac muscle SR.
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    Differential regulation of Na+/H+ exchange and H+ -ATPase by pH and HCO 3 − in kidney proximal tubules (1995)
    Springer
    The journal of membrane biology 144 (1995), S. 209-216 
    Details
    ISSN: 1432-1424
    Keywords: Na+/H+ exchange ; H+-ATPase ; Proximal tubules ; Kidney ; Acid-base ; pH
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract This study examines the effects of acute in vitro acid-base disorders on Na+/H+ and H+-ATPase transporters in rabbit kidney proximal tubules (PT). PT suspensions were incubated in solutions with varying acid base conditions for 45 min and utilized for brush border membrane (BBM) vesicles preparation. BBM vesicles were studied for Na+/H+ exchange activity (assayed by 22Na+ influx) or abundance (using NHE-3 specific antibody) and H+-ATPase transporter abundance (using antibody against the 31 kDa subunit). The Na+/ H+ exchanger activity increased by 55% in metabolic acidosis (pH 6.5, HCO 3 − 3 mm) and decreased by 41% in metabolic alkalosis (pH 8.0, HCO 3 − 90 mm). The abundance of NHE-3 remained constant in acidic, control, and alkalotic groups. H+-ATPase abundance, however, decreased in metabolic acidosis and increased in metabolic alkalosis by 57% and 42%, respectively. In PT suspensions incubated in isohydric conditions (pH 7.4), Na+/H+ exchanger activity increased by 29% in high HCO 3 − group (HCO 3 − 96 mm) and decreased by 16% in the low HCO 3 − groups (HCO 3 − 7mm. The NHE-3 abundance remained constant in high, normal, and low [HCO 3 − ] tubules. The abundance of H+-ATPase, however, increased by 82% in high [HCO 3 − ] and decreased by 77% in the low [HCO 3 − ] tubules. In PT suspensions incubated in varying pCO2 and constant [HCO 3 − ], Na+/H+ exchanger activity increased by 35% in high pCO2 (20% pCO2, respiratory acidosis) and decreased by 32% in low pCO2 (1.5% pCO2, respiratory alkalosis) tubules. The NHE-3 abundance remained unchanged in high, normal, and low pCO2 tubules. However, the H+-ATPase abundance increased by 74% in high pCO2 and decreased by 69% in low pCO2 tubules. The results of these studies suggest that the luminal Na+/H+ exchanger is predominantly regulated by pH whereas H+-ATPase is mainly regulated by [HCO 3 − ] and/ or pCO2. They further suggest that the adaptive changes in H+-ATPase transporter are likely mediated via endocytic/exocytic pathway whereas the adaptive changes in Na+/H+ exchanger are via the nonendocytic/exocytic pathway. The excellent technical assistance of Yollanda J. Hattabaugh, Gwen L. Bizal, and L. Yang is greatly appreciated. Portions of these studies were presented at the annual meeting of the American Society of Nephrology, Boston, MA, November 1993, and published in abstract form (J.Am.Soc.Neph. 4:840A, 1993)
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    Effects of internal ph on the nonselective cation channel from the mouse collecting tubule (1995)
    Springer
    The journal of membrane biology 148 (1995), S. 83-90 
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    ISSN: 1432-1424
    Keywords: Cation channel ; pH ; Nucleotides
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract We investigated the effects of internal pH on Ca-activated, nucleotide-inhibited nonselective cation channels in the basolateral membranes of mouse collecting tubules, using the inside-out variant of the patch clamp technique. pH modulated the channel open probability (P o ), giving a bell-shaped curve peaking at pH 6.8/7.0: P o at pH 6.0 was 11±6% of P o at pH 7.2 and 32 ±7% at pH 8.0. The open and closed time distributions, best fitted to the sum of two exponentials, were differently sensitive to acid and alkaline conditions. Low pH reduced the short and long open times to 38 and 24% of their pH 7.2 values, while high pH produced a 4-fold increase in the long closed time. As previously reported, 4-acetamido-4′-isothiocyanatostilbene-2,2′-disulfonic acid (SITS) induced a quasi-permanent opening of the channel. The inhibition of the channel produced by high pH disappeared in the presence of SITS, while the inhibition produced by low pH was unaffected. These results suggest that the pH dependence of the channel is due to two separate mechanisms. pH was without effect on the ATP-evoked inhibition of the channel, while high pH profoundly reduced the steepness of the AMP inhibition curve, without altering the half-maximal inhibitory AMP concentration.
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    Detection of the apomictic mode of reproduction in maize-Tripsacum hybrids using maize RFLP markers (1995)
    Springer
    Theoretical and applied genetics 90 (1995), S. 1198-1203 
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    ISSN: 1432-2242
    Keywords: Diplospory ; RFLP ; Bulk-segregant analysis ; Genome similarity ; Intergeneric hybrids ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Polyploid plants in the genus Tripsacum, a wild relative of maize, reproduce through gametophytic apomixis of the diplosporous type, an asexual mode of reproduction through seed. Moving gene(s) responsible for the apomictic trait into crop plants would open new areas in plant breeding and agriculture. Efforts to transfer apomixis from Tripsacum into maize at CIMMYT resulted in numerou intergeneric F1 hybrids obtained from various Tripsacum species. A bulk-segregant analysis was carried out to identify molecular markers linked to diplospory in T. dactyloides. This was possible because of numerous genome similarities among related species in the Andropogoneae. On the basis of maize RFLP probes, three restriction fragments co-segregating with diplospory were identified in one maize-Tripsacum dactyloides F1 population that segregated 1∶1 for the mode of reproduction. The markers were also found to be linked in the maize RFLP map, on the distal end of the long arm of chromosome 6. These results support a simple inheritance of diplospory in Tripsacum. Manipulation of the mode of reproduction in maize-Tripsacum backcross generations, and implications for the transfer of apomixis into maize, are discussed.
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    Presence of an oxytocin-like peptide in the hypothalamus and neurohypophysis of a turtle (Mauremys caspica) and a snake (Natrix maura) (1995)
    Springer
    Cell & tissue research 279 (1995), S. 75-84 
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    ISSN: 1432-0878
    Keywords: Oxytocin ; Neurophysin ; Vasotocin ; Mesotocin ; Suprachiasmatic nucleus ; Medial nucleus of the infundibular recess ; Immunocytochemistry ; Natrix maura (Serpentes) ; Mauremys caspica (Chelonia)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The probable presence of oxytocin in the hypothalamo-hypophysial system of two reptilian species, the snake Natrix maura and the turtle Mauremys caspica, was re-investigated. A high-pressure liquid chromatographic analysis of the turtle neural lobe revealed the existence of vasotocin, mesotocin, and a third compound co-eluting with oxytocin. Brains from both species were fixed by vascular perfusion with Bouin's fluid. Adjacent paraffin sections were immunostained using antisera against the following substances: (1) bovine oxytocin-neurophysin; (2) a mixture of bovine oxytocin-neurophysin and vasopressin-neurophysin; (3) dogfish neurophysins; (4) oxytocin; (5) arginine-vasotocin; (6) mesotocin; (7) somatostatin. Immunoreactivity against oxytocin was found in parvocellular neurons of the snake suprachiasmatic nucleus and cerebrospinal-fluid contacting neurons of the medial nucleus of the infundibular recess of both species, the latter immunoreactivity being much more conspicuous in the turtle. Numerous fibers containing immunoreactive oxytocin extended between the medial nucleus of the infundibular recess, and the internal region of the medium eminence and the neural lobe. The oxytocin-immunoreactivity in all locations was completely abolished by preabsorption of the anti-oxytocin serum with three different oxytocin preparations. None of the neurons of the suprachiasmatic and medial nucleus of the infundibular recess, including the oxytocin-immunoreactive elements, reacted with either the antineurophysin sera used, or the anti-vasotocin or anti-mesotocin antibodies. The possible existence of a reptilian oxytocin-neurophysin is discussed. The alternative that, in the reptilian hypothalamus, neurons synthesize a compound closely related to, but different from oxytocin is also considered.
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    The biased intracellular accumulation of the β-subunit of salmon gonadotropin (GTH II) in the pituitary of rainbow trout Oncorhynchus mykiss, during gametogenesis (1995)
    Springer
    Cell & tissue research 279 (1995), S. 93-99 
    Details
    ISSN: 1432-0878
    Keywords: Pituitary gland ; Gonadotropin ; Subunits ; Gonadotropes ; Immunocytochemistry ; Immunoblotting ; Oncorhynchus mykiss (Teleostei)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Salmon gonadotropin (GTH II) is a heterodimeric glycoprotein hormone (α and IIβ subunits), serving as a maturational GTH, and is produced in a specific gonadotropic cell-type (GTH II-cells) containing small granules and large globules. In trout GTH II-cells, double immunolabeling for the α- and IIβ-subunits shows that colocalization of the α- and IIβ-immunolabeling is confined to the small granules, indicating storage of functional GTH II. On the other hand, α-immunolabeling is absent in the large globules, even though IIβ labeling is abundant throughout the period of seasonal gametogenesis. The α-specific antiserum recognizes the intact α-subunit as well as the reduced and deglycosylated α-subunits by immunoblotting. These results indicate that an accumulation of the IIβ-subunit is specifically generated in the large globules of these cells. In fact, with sexual maturity, the quantity of IIβ-subunits becomes elevated in the trout pituitary due to a marked increase in GTH II-cells containing many large globules. However, the derivation and function of the large globules and the fate of their contained IIβ-subunits remains unknown.
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    URL: http://dx.doi.org/10.1007/BF00300695
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    Regeneration and post-metamorphic development of the central nervous system in the protochordate Ciona intestinalis: a study with monoclonal antibodies (1995)
    Springer
    Cell & tissue research 279 (1995), S. 421-432 
    Details
    ISSN: 1432-0878
    Keywords: Trans-differentiation ; Proliferation ; Bromodeoxyuridine ; Immunocytochemistry ; Regeneration ; Ciona intestinalis (Tunicata)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract In this study, we use three monoclonal antibodies that recognise antigens present in the central nervous system of the ascidian Ciona intestinalis to study regeneration and post-metamorphic development of the neural ganglion. We have also used bromodeoxyuridine labelling to study generation of the neuronal precursor cells. The first antibody, CiN 1, recognises all neurones in the ganglion, whereas the second, CiN 2, recognises only a subpopulation of the large cortical neurones. Western blotting studies show that CiN 2 recognises two membrane-bound glycoproteins of apparent Mr 129 and 100 kDa. CiN 1 is not reactive on Western blots. Immunocytochemical studies with these antibodies show that CiN 1-immunoreactive neurone-like cells are present at the site of regeneration as early as 5–7 days post-ablation, a sub-population of CiN 2-immunoreactive cells being detected by 9–12 days post-ablation. The third antibody, ECM 1, stains extracellular matrix components and recognises two diffuse bands on Western blots of whole-body and ganglion homogenates. The temporal and spatial pattern of appearance of CiN 1 and CiN 2 immunoreactivity both during post-metamorphic development and in regeneration occurs in the same sequence in both processes. Studies with bromodeoxyuridine show labelled nuclei in some neurones in the regenerating ganglion. Plausibly these originate from the dorsal strand, an epithelial tube that reforms by cell proliferation during the initial phases of regeneration. A second population of cells, the large cortical neurones, do not incorporate bromodeoxyuridine and thus must have been born prior to the onset of regeneration. This latter finding indicates a mechanism involving trans-differentiation of other cell types or differentiation of long-lived totipotent stem cells.
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    URL: http://dx.doi.org/10.1007/BF00318500
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    Presence of embryonic myosin in normal postural muscles of the adult rat (1995)
    Springer
    Cell & tissue research 280 (1995), S. 541-548 
    Details
    ISSN: 1432-0878
    Keywords: Key words: Musle ; striated ; skeletal ; Regeneration ; Myosin ; Immunocytochemistry ; Rat (Sprague Dawley)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. Indirect immunofluorescence was used to localize embryonic myosin heavy chains in soleus, adductor longus, tibialis anterior, plantaris, and extensor digitorum longus muscles of 6-month-old rats. A monoclonal antibody (2B6), specifically recognizing rat embryonic myosin, was applied to unfixed, transverse, frozen sections. The number of embryonic myosin-positive (EMP) extrafusal fibers was expressed as a percentage of the total number of fibers. EMP extrafusal fibers were only seen in the soleus and adductor longus muscles, both postural muscles. Approximately 1% of the soleus muscle fibers appeared positively stained for embryonic myosin. The majority of such fibers had a small diameter (〈500 μ2), appeared intensely fluorescent, and typically contained central nuclei. Re-expression of embryonic myosin due to spontaneous fiber denervation is not a likely factor in this study, since alpha-bungarotoxin and N-CAM localization were restricted to the motor end-plate region of EMP fibers. Since embryonic myosin was shown to disappear in all normal-sized myofibers by 2 to 3 months of age, the results suggest that the EMP extrafusal fibers seen in postural muscles of 6 to 12-month-old animals are regenerating myofibers. We speculate that a small number of muscle fibers may be regenerating in normal, adult postural muscles, in response to fiber damage possibly caused by excessive recruitment or overloading.
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    URL: http://dx.doi.org/10.1007/BF00318358
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    Development of melanin-concentrating hormone-immunoreactive elements in the brain of gilthead seabream (Sparus auratus) (1995)
    Springer
    Cell & tissue research 282 (1995), S. 523-526 
    Details
    ISSN: 1432-0878
    Keywords: Key words: Melanin-concentrating hormone ; Immunocytochemistry ; Development ; ontogenetic ; Sparus auratus (Teleostei)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. The development of the hypothalamic melanin-concentrating hormone (MCH) system of the teleost Sparus auratus has been studied by immunocytochemistry using an anti-salmon MCH serum. Immunoreactive perikarya and fibers are found in embryos, larvae, and juvenile specimens. In juveniles, most labeled neurons are present in the nucleus lateralis tuberis; some are dispersed in the nucleus recessus lateralis and nucleus periventricularis posterior. From the nucleus lateralis tuberis, MCH neurons project a conspicuous tract of fibers to the ventral hypothalamus; this penetrates the pituitary stalk and reaches the neurohypophysis. Most fibers end close to the cells of the pars intermedia, and some reach the adenohypophysial rostral pars distalis. Immunoreactive fibers can also be seen in extrahypophysial localizations, such as the preoptic region and the nucleus sacci vasculosi. In embryos, MCH-immunoreactive neurons first appear at 36 h post-fertilization in the ventrolateral margin of the developing hypothalamus. In larvae, at 4 days post-hatching, perikarya can be observed in the ventrolateral border of the hypothalamus and in the mid-hypothalamus, near the ventricle. At 26 days post-hatching, MCH perikarya are restricted to the nucleus lateralis tuberis. The neurohypophysis possesses MCH-immunoreactive fibers from the second day post-hatching. The results indicate that MCH plays a role in larval development with respect to skin melanophores and cells that secrete melanocyte-stimulating hormone.
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    URL: http://dx.doi.org/10.1007/s004410050504
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    Ontogenetic development of neuropeptide Y-like-immunoreactive cells in the gastroenteropancreatic endocrine system of the dogfish (1995)
    Springer
    Cell & tissue research 282 (1995), S. 33-40 
    Details
    ISSN: 1432-0878
    Keywords: Key words: Neuropeptide Y ; Gastroenteropancreatic (GEP) endocrine system ; Development ; ontogenetic ; Vitellointestinal duct ; Pancreas ; exocrine ; Pancreas ; endocrine ; Immunocytochemistry ; Scyliorhinus torazame (Elasmobranchii)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. This immunocytochemical study was carried out to elucidate the ontogenetic development of neuropeptide Y-like-immunoreactive cells in the gastroenteropancreatic endocrine system of the cloudy dogfish, Scyliorhinus torazame. Immunostained cells first appeared in the pancreas of the embryo at the 15-mm stage, and were also detected in the vitellointestinal duct of the yolk stalk at the 20-mm stage. These cells were polymorphic, with occasional processes that were sometimes directed toward the vascular wall or into the cavity of the vitellointestinal duct. At the 34-mm stage, immunostained cells could also be found in the proximal part of the spiral intestine and, by the 74-mm stage, immunopositive cells were present in the gastric mucosa. In the gut and pancreas, the cells gradually increased in number with development, whereas in the vitellointestinal duct and internal yolk sac, they decreased and seemed to disappear following hatching. Thus, in juveniles, the distribution of the neuropeptide Y-like-immunoreactive cells in the gastroenteropancreatic endocrine system had attained that of adults. Electron-microscopic immunocytochemistry demonstrated that, in the labeled cells of the vitellointestinal duct, the neuropeptide Y-like antigen was located in cytoplasmic granules, as in the cells of the gut and pancreas.
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    Rat intestinal galactoside-binding lectin L-36 functions as a structural protein in the superficial squamous cells of the esophageal epithelium (1995)
    Springer
    Cell & tissue research 281 (1995), S. 77-83 
    Details
    ISSN: 1432-0878
    Keywords: Key words: Esophagus ; Epithelial cells ; Intestinal lectin ; L-36 ; RI-H fragment ; Immunocytochemistry ; Rat (Wistar)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. Using an affinity purified antibody raised against the RI-H fragment of rat intestinal lectin L-36, the latter protein has been identified within the esophageal epithelium by means of ultracryotomy followed by immunogold labeling. The epithelium consists of 4 morphologically distinct cell-types, namely, the basal, spiny, granular and squamous cells, and each of these exhibits a different immunolabeling pattern. The basal cells form a layer on the basal lamina, and in these a diffuse cytoplasmic staining is observed. This basal cell layer is overlaid by spiny cells that extend many cell processes into wide intercellular spaces. In these cells, immunogold particles are found only on small granular inclusions consisting of an electron-lucent homogeneous substance. The granular cells form a third layer over the spiny cells, and are characterized by a number of large granular inclusions with an electron-dense core rimmed by a less electron-dense substance. Immunogold labeling is found on these granules, both on the core and peripheral region. Squamous cell-types constitute the most superficial layer of the epithelium. They are without granular inclusions, and immunogold labeling is confined to the cytoplasmic surface of the thickened plasma membrane. These findings suggest that L-36 is produced in the basal cells as free cytosolic protein, then becomes progressively aggregated into the granular inclusions of the spiny and granular cells, and is eventually transferred onto the cytoplasmic surface of the squamous cell plasma membrane where it may interact with complementary glycoconjugate(s) located at this site. The membrane lining substance thus formed may play a role in stabilizing the squamous cell membranes, thereby maintaining the structural integrity of the epithelium against mechanical stress coming from the esophageal lumen.
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    Immunocytochemical localisation of some lysosomal hydrolases, their presence in luminal fluid and their directional secretion by human epididymal cells in culture (1995)
    Springer
    Cell & tissue research 280 (1995), S. 415-425 
    Details
    ISSN: 1432-0878
    Keywords: Key words: Epididymis ; Efferent ducts ; Cell culture ; Immunocytochemistry ; Immunoprecipitation ; Man
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. The way in which the human epididymis modifies spermatozoa during their sojourn in this structure might be clarified by knowledge of the nature of its secretions. We have examined the presence of several lysosomal hydrolases in human epididymal tissue and fluids, and their synthesis and secretion by monolayer cultures. Tissues were obtained from men undergoing orchidectomy for prostatic carcinoma. The enzymes cathepsin D and acid α-glucosidase were localised in the lysosomes of epithelial cells from the corpus epididymidis, by an immunocytochemical technique. Cathepsin D was also found in epithelial cells of the efferent ducts within lysosomes, apical vesicles and multivesicular bodies. No immunolocalisation of acid glucosidase in the efferent ducts or on the microvilli of the corpus was demonstrable. Cathepsin D, β-hexosaminidase (N-acetylglucosaminidase) and α-glucosidase were measurable in the luminal fluid from the human corpus epididymidis; β-hexosaminidase was secreted into the culture medium by confluent monolayers of epididymal and efferent duct cells. Immunoprecipitation of cell extracts and culture medium of these cultures incubated with 35S-methionine revealed that the precursors of cathepsin D and β-hexosaminidase were synthesized and secreted by such monolayers. Thus, active lytic enzymes are secreted by the human epididymis and could modify sperm membranes.
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    URL: http://dx.doi.org/10.1007/BF00307815
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    Immunolocalization of the Na,K-ATPase in photoreceptor cells of the moth Manduca sexta-evidence for Na,K-ATPase on both the nonmicrovillar and the microvillar domains of the plasma membrane (1995)
    Springer
    Cell & tissue research 281 (1995), S. 119-126 
    Details
    ISSN: 1432-0878
    Keywords: Compound eye ; Photoreceptor cells ; Ion pumps ; Polarity ; Immunocytochemistry ; Manduca sexta (Insecta)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Immunohistochemical and physiological studies on various insect photoreceptors have demonstrated that the Na,K-ATPase (sodium pump) is restricted to the nonreceptive nonmicrovillar area of the plasma membrane. Here, we examined the distribution of the Na,K-ATPase in photoreceptor cells of the superposition-type compound eye in the moth Manduca sexta. Using immunofluorescent and immunogold cytochemistry, we show that the Na,K-ATPase is localized to both the nonmicrovillar and the microvillar parts of the plasma membrane. Manduca photoreceptors thus deviate from the common concept that the sodium pump and the molecular components of the photoreceptive machinery reside on different domains of the plasma membrane.
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    Putative neurohemal areas in the peripheral nervous system of an insect, Gryllus bimaculatus, revealed by immunocytochemistry (1995)
    Springer
    Cell & tissue research 281 (1995), S. 43-61 
    Details
    ISSN: 1432-0878
    Keywords: Neurohemal areas ; Neuropeptides ; Monoamines ; Immunocytochemistry ; Nervous system, insect ; Gryllus bimaculatus (Insecta)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The morphology and position of putative neurohemal areas in the peripheral nervous system (ventral nerve cord and retrocerebral complex) of the cricket Gryllus bimaculatus are described. By using antisera to the amines dopamine, histamine, octopamine, and serotonin, and the neuropeptides crustacean cardioactive peptide, FMRFamide, leucokinin 1, and proctolin, an extensive system of varicose fibers has been detected throughout the nerves of all neuromeres, except for nerve 2 of the prothoracic ganglion. Immunoreactive varicose fibers occur mainly in a superficial position at the neurilemma, indicating neurosecretory storage and release of neuroactive compounds. The varicose fibers are projections from central or peripheral neurons that may extend over more than one segment. The peripheral fiber varicosities show segment-specific arrangements for each of the substances investigated. Immunoreactivity to histamine and octopamine is mainly found in the nerves of abdominal segments, whereas serotonin immunoreactivity is concentrated in subesophageal and terminal ganglion nerves. Immunoreactivity to FMRFamide and crustacean cardioactive peptide is widespread throughout all segments. Structures immunoreactive to leucokinin 1 are present in abdominal nerves, and proctolin immunostaining is found in the terminal ganglion and thoracic nerves. Codistribution of peripheral varicose fiber plexuses is regularly seen for amines and peptides, whereas the colocalization of substances in neurons has not been detected for any of the neuroactive compounds investigated. The varicose fiber system is regarded as complementary to the classical neurohemal organs.
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    Immunolocalization of interleukin-1α in rat mandibular molars and its enhancement after in vivo injection of epidermal growth factor (1995)
    Springer
    Cell & tissue research 280 (1995), S. 21-26 
    Details
    ISSN: 1432-0878
    Keywords: Interleukin ; Stellate reticulum ; Immunocytochemistry ; Epidermal growth factor ; Interleukin-1 receptor type I messenger RNA ; Tooth eruption ; Rat (Sprague Dawley)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Immunolocalization of interleukin-1α in the first mandibular molars of rats from day 0–12 postnatally showed that the protein was localized in the epithelial stellate reticulum adjacent to the dental follicle. Staining of the stellate reticulum was most prominent in the early days postnatally and was absent by postnatal day 11. Injection of epidermal growth factor into rats at day 0 greatly increased the intensity of the staining for interleukin-1α in the stellate reticulum. Epidermal growth factor (EGF) enhanced the gene expression of interleukin-1α in stellate reticulum cells in vitro, and this study suggests there is enhanced translation of interleukin-1α messenger RNA in the stellate reticulum following EGF injection. In turn, the interleukin-1α may exert its effect on the dental follicle cells adjacent to the stellate reticulum because EGF also enhanced expression of the interleukin-1 receptor type I messenger RNA in cultured dental follicle cells as well as enhancing its expression in vivo. In view of the fact that injection of EGF will stimulate precocious eruption of teeth, its stimulus of interleukin-1α synthesis in the stellate reticulum may be the mechanism by which EGF initiates a cascade of molecular events to signal the onset of tooth eruption.
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    Expression of the endogenous 14-kDa β-galactoside-binding lectin galectin in normal human skin (1995)
    Springer
    Cell & tissue research 280 (1995), S. 1-10 
    Details
    ISSN: 1432-0878
    Keywords: Key words: Galectin ; β-Galactoside-binding lectin ; Human ; Skin ; Immunocytochemistry ; Immunohistochemistry ; Hybridization ; in situ ; Langerhans cell ; Man
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. The localization of an endogenous 14-kDa β-galactoside-binding lectin (galectin) and its pattern of gene expression were examined in normal human skin by light- and electron microscopy. Under the light microscope, immunostaining of 14-kDa galectin was observed in the cell membrane of cells in the basal and spinous layers of the epidermis. Galectin was also found in the Langerhans cells, as shown by double labeling using anti-14-kDa galectin and anti-CD1a antibodi es. In the dermis, immunostaining for the 14-kDa galectin was positive in the extracellular matrix and fibroblasts. At the electron-microscopic level of resolution, galectin was located primarily along the plasma membrane of keratinocytes, and in both the cytoplasm and nucleus of Langerhans cells in the epidermis, whereas in the dermis it was detected in the extracellular matrix and in both the nucleus and cytoplasm of fibroblasts. The gene expression of 14-kDa galectin was visualized by the HRP-staining me thod following in situ hybridization techniques. The expression was detected in the cytoplasm of cells in the basal and spinous layers of the epidermis; whereas, in the dermis, it was detected in the cytoplasm of fibroblasts. Moreover, SDS-polyacrylamide gel electrophoresis and lectin-blot analysis revealed that this galectin bound to glycoproteins of approximately 17, 62, and 72 kDa in the epidermis and to those of 29, 54, and 220 kDa in the dermis. The present study indicates that 1) normal human skin produces the β-galactoside-binding 14-kDa galectin, and 2) this galectin is located in both the epidermis, particularly in the keratinocytes and Langerhans cells, and in the dermis. These results suggest that galectin is important for cell-cell contact and/or adhesion in the epidermis and for cell-extracellular matrix interaction in the dermis.
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    Expression of the endogenous 14-kDa β-galactoside-binding lectin galectin in normal human skin (1995)
    Springer
    Cell & tissue research 280 (1995), S. 1-10 
    Details
    ISSN: 1432-0878
    Keywords: Galectin ; β-Galactoside-binding lectin ; Human ; Skin ; Immunocytochemistry ; Immunohistochemistry ; Hybridization, in situ ; Langerhans cell ; Man
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The localization of an endogenous 14-kDa β-galactoside-binding lectin (galectin) and its pattern of gene expression were examined in normal human skin by light- and electron microscopy. Under the light microscope, immunostaining of 14-kDa galectin was observed in the cell membrane of cells in the basal and spinous layers of the epidermis. Galectin was also found in the Langerhans cells, as shown by double labeling using anti-14-kDa galectin and anti-CD1a antibodies. In the dermis, immunostaining for the 14-kDa galectin was positive in the extracellular matrix and fibroblasts. At the electron-microscopic level of resolution, galectin was located primarily along the plasma membrane of keratinocytes, and in both the cytoplasm and nucleus of Langerhans cells in the epidermis, whereas in the dermis it was detected in the extracellular matrix and in both the nucleus and cytoplasm of fibroblasts. The gene expression of 14-kDa galectin was visualized by the HRP-staining method following in situ hybridization techniques. The expression was detected in the cytoplasm of cells in the basal and spinous layers of the epidermis; whereas, in the dermis, it was detected in the cytoplasm of fibroblasts. Moreover, SDS-polyacrylamide gel electrophoresis and lectin-blot analysis revealed that this galectin bound to glycoproteins of approximately 17, 62, and 72 kDa in the epidermis and to those of 29, 54, and 220 kDa in the dermis. The present study indicates that 1) normal human skin produces the β-galactoside-binding 14-kDa galectin, and 2) this galectin is located in both the epidermis, particularly in the keratinocytes and Langerhans cells, and in the dermis. These results suggest that galectin is important for cell-cell contact and/or adhesion in the epidermis and for cell-extracellular matrix interaction in the dermis.
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    Characterization and localization of an Mr 225 kDa polypeptide specifically involved in the defence mechanisms of the clam Tapes semidecussatus (1995)
    Springer
    Cell & tissue research 280 (1995), S. 27-37 
    Details
    ISSN: 1432-0878
    Keywords: Defence mechanisms ; Encapsulation ; Granulocytes ; Immunocytochemistry ; Parasitism ; Perkinsus sp. (Protozoa) ; Tapes semidecussatus (Mollusca)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Parasitosis by the trophozoite protozoan Perkinsus sp. (Apicomplexa, Perkinsea) induces in the gill filaments of the clam Tapes semidecussatus (Mollusca, Bivalvia) a cellular reaction, which is constituted by infiltrated granulocytes. This cellular reaction has characteristics of those of a holocrine gland, since the parasites are encapsulated by the secretion product of the granulocytes after cell death. An enriched fraction of prezoosporangia and their associated capsule was obtained after culture of the parasitized gills in fluid thioglycollate medium. Specific polypeptides from this fraction were separated by SDS-PAGE and isolated for rabbit immunizations. The serum obtained against an Mr 225 kDa polypeptide, revealed its exclusive localization in the capsule and in the granules of the infiltrated granulocytes, thus indicating that this polypeptide is synthesized by these cells and secreted, in a polarized way, around the trophozoites resulting in their encapsulation. Selective deglycosylation of the polypeptide, by Endo H and alkaline β-elimination, did not show an effect on its molecular weight or antibody recognition. Furthermore, the absence of the 225 kDa band in the Western-blots of non-parasitized gills indicated the specific association of this polypeptide with the parasitosis. Finally, this is the first tissue-specific factor described in molluscs in relation to defence mechanisms.
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    Immunocytochemical localization of ribonuclease in yolk granules of adult Rana cttesbeiana oocytes (1995)
    Springer
    Cell & tissue research 280 (1995), S. 259-265 
    Details
    ISSN: 1432-0878
    Keywords: Oocyte ; Yolk granules ; Ribonuclease ; Immunocytochemistry ; Bullfrog, Rana catesbeiana (Anura)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract To determine the localization of the pyrimidine-guanine sequence-specific ribonuclease in Rana catesbeiana (bullfrog) oocytes, the RNase was first isolated and used to prepare a specific rabbit antiserum. Only one protein of similar molecular size to the RNase was immunoprecipitated from ovary homogenate by the antiserum, but two bands were observed by Western blotting analysis. These two proteins were shown by further purification of antibody and Western blotting analysis to have similar antigenicity. Immunoprecipitation and Western blotting of tissue homogenates showed that the RNase was found predominantly in the ovary, but not in other tissues. The specific localization of the RNase was determined by immuno-electron microscopy of oocyte sections incubated with the specific antiserum; the yolk granules, but not other organelles, were found to contain the RNase. Most of the RNase was evenly distributed in the lateral amorphous area of the yolk granule but not in the central yolk crystal area which contains stored vitellogenin proteins. Our results indicate that the RNase is compartmentalized in the yolk granules of oocytes, which might prevent damage to cellular RNAs.
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    Rat intestinal galactoside-binding lectin L-36 functions as a structural protein in the superficial squamous cells of the esophageal epithelium (1995)
    Springer
    Cell & tissue research 281 (1995), S. 77-83 
    Details
    ISSN: 1432-0878
    Keywords: Esophagus ; Epithelial cells ; Intestinal lectin, L-36 ; RI-H fragment ; Immunocytochemistry ; Rat (Wistar)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Using an affinity purified antibody raised against the RI-H fragment of rat intestinal lectin L-36, the latter protein has been identified within the esophageal epithelium by means of ultracryotomy followed by immunogold labeling. The epithelium consists of 4 morphologically distinct cell-types, namely, the basal, spiny, granular and squamous cells, and each of these exhibits a different immunolabeling pattern. The basal cells form a layer on the basal lamina, and in these a diffuse cytoplasmic staining is observed. This basal cell layer is overlaid by spiny cells that extend many cell processes into wide intercellular spaces. In these cells, immunogold particles are found only on small granular inclusions consisting of an electron-lucent homogeneous substance. The granular cells from a third layer over the spiny cells, and are characterized by a number of large granular inclusions with an electron-dense core rimmed by a less electron-dense substance. Immunogold labeling is found on these granules, both on the core and peripheral region. Squamous cell-types constitute the most superficial layer of the epithelium. They are without granular inclusions, and immunogold labeling is confined to the cytoplasmic surface of the thickened plasma membrane. These findings suggest that L-36 is produced in the basal cells as free cytosolic protein, then becomes progressively aggregated into the granular inclusions of the spiny and granular cells, and is eventually transferred onto the cytoplasmic surface of the squamous cell plasma membrane where it may interact with complementary glycoconjugate(s) located at this site. The membrane lining substance thus formed may play a role in stabilizing the squamous cell membranes, thereby maintaining the structural integrity of the epithelium against mechanical stress coming from the esophageal lumen.
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    Localization of integrin subunits α6 and β1 during somitogenesis in the long-tailed macaque (M. fascicularis) (1995)
    Springer
    Cell & tissue research 281 (1995), S. 101-108 
    Details
    ISSN: 1432-0878
    Keywords: Somite ; Intergin ; Extracellular matrix, structures ; Embryo ; Laminin ; Immunocytochemistry ; Macaca fascicularis (Primates)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The distribution of integrin subunits α6 and β1, and the α6β1 integrin ligand, laminin, was examined during somitogenesis in developmental stages 11, 13, and 16 in the long-tailed macaque, using peroxidase immunocytochemistry. Within differentiating somites in stage 11, α6 expression was observed in the sclerotome, basal surface of dermamyotomal cells adjacent to the basal lamina and on scattered cells throughout the dermamyotome. In further advanced somites in stages 13 and 16, α6 immunoreactivity become restricted to the myotome, α6 was expressed on mesenchymal core cells within the myocele of undifferentiated epitheliod somites and the ventromedial wall of somites commencing differentiation at each stage. β1 distribution resembled that of α6 in stage 11 somitic tissue, however, it remained present on myotome and sclerotome cells in the later stages, and was also expressed on dermatomal cells in stage 16. Laminin immunoreactivity, while more intense and prevalent than α6 and β1 in each stage examined, occurred on the same somite cell populations as the 2 integrin subunits. These results show a defined distribution of α6 on somitic tissue, and suggest this integrin is involved in somite differentiation. They also support a possible role for α6 in myoblast formation and migration. Overlapping of β1 and laminin immunoreactivity with that of α6 further suggests that α6 paris with β1 as a functional heterodimer for laminin in defined somitic regions.
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    Immunocytochemical, electrophoresis, and immunoblot analysis of Heliothis virescens gap junctions isolated in the presence and absence of protease inhibitors (1995)
    Springer
    Cell & tissue research 281 (1995), S. 179-186 
    Details
    ISSN: 1432-0878
    Keywords: Key words: Gap junction ; Intercellular junction ; Insect ; Arthropod ; Immunocytochemistry ; Heliothis virescens (Insecta)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. Gap junction-enriched fractions were prepared from larvae of the tobacco budworm Heliothis virescens using the NaOH procedure in the presence or absence of protease inhibitors and were analyzed by SDS-PAGE, immunoblotting and EM immunocytochemistry. Protease inhibitor fractions contained a 48-kDa protein in addition to the ∼10 proteins in fractions with and without inhibitors. Three polyclonal antibodies were used as probes for gap junction plaques and proteins: R16, against an ∼40-kDa candidate gap junction protein from Drosophila melanogaster; R17, against the 40-kDa candidate gap junction protein from H. virescens; and R18AP, an affinity purified antibody against a consensus sequence of N-terminal amino acids 2–21 of the H. virescens 40-kDa protein. R16, R17, and R18AP stain the 40- and 48-kDa proteins, R16 and R18AP stain a 64-kDa protein, and R16 stains an ∼30-kDa protein in the absence of inhibitors. Inclusion of protease inhibitors had no effect on gap junction ultrastructure. R16 and R17 label gap junction plaques in crude membrane and NaOH fractions, whereas R18AP exhibits only a low level of reactivity with gap junctions in crude membrane fractions and none with gap junctions in NaOH fractions. The results show that the 30-, 40-, 48- and 64-kDa proteins are immunologically related and are associated with gap junctions in H. virescens, the N-terminus of the 40-kDa protein is relatively inaccessible or easily lost, and the 48-kDa protein is protease-sensitive.
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    URL: http://dx.doi.org/10.1007/BF00307972
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    Unusual distribution of tubulin isoforms in the snail Lymnaea stagnalis (1995)
    Springer
    Cell & tissue research 281 (1995), S. 507-515 
    Details
    ISSN: 1432-0878
    Keywords: Microtubules ; Isoforms ; Nervous system ; Locomotion ; Cilia ; Immunocytochemistry ; Western blotting ; Lymnaea stagnalis (Mollusca)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Immunocytochemistry and Western blotting techniques demonstrated that the nervous system and foot of the pond snail Lymnaea stagnalis are rich sources of tubulin, which can be extracted and assembled in vitro in the presence of taxol. Various broad-spectrum antibodies raised against α-tubulin and β-tubulin yielded qualitatively similar results. One monoclonal antibody to trypanosome α-tubulin, however, labelled α-tubulin more strongly on both probed sections and Western blots. Cytochemistry and immunoblotting revealed that tyrosinated tubulin constitutes a large proportion of total α-tubulin in locomotor cilia of the foot and in axons of the nervous system. Detyrosinated tubulin also appeared to be abundant in the foot cilia but only a very faint band of detyrosinated tubulin was found on protein blots extracted from the central ganglia, and staining was barely detectable in central ganglia or peripheral nerves. Similarly, acetylated tubulin appeared to be abundant in foot cilia, but Western blotting indicated only low levels of acetylated tubulin in the nervous system. Immunocytochemistry indicated that, while most neurons possessed little or no acetylated tubulin, a small number of axons contained significant amounts of this isoform. Thus, while a large amount of tubulin was expected in the nervous system and locomotor cilia of L. stagnalis, the observed distribution of isoforms was unanticipated. Specifically, neurons of other organisms have generally been reported to contain substantial amounts of both detyrosinated α-tubulin and acetylated α-tubulin. Our results indicate that such findings cannot be generalized across all species. L. stagnalis, with its well studied nervous system and unusual distribution of tubulin isoforms, may prove to be particularly useful for studying the roles of tubulin isoforms in microtubule function and cell activity.
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    URL: http://dx.doi.org/10.1007/BF00417868
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    Immunocytochemical characterization of the accessory medulla in the cockroach Leucophaea maderae (1995)
    Springer
    Cell & tissue research 282 (1995), S. 3-19 
    Details
    ISSN: 1432-0878
    Keywords: Circadian rhythm ; Colocalization ; Immunocytochemistry ; Brain (CNS), invertebrate ; Optic lobe ; Pigment-dispersing hormone, insect ; Leucophaea maderae (Insecta)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Several lines of evidence suggest that pigment-dispersing hormone-immunoreactive neurons with ramifications in the accessory medulla are involved in the circadian system of insects. The present study provides a detailed analysis of the anatomical and neurochemical organization of the accessory medulla in the brain of the cockroach Leucophaea maderae. We show that the accessory medulla is compartmentalized into central dense nodular neuropil surrounded by a shell of coarse fibers. It is innervated by neurons immunoreactive to antisera against serotonin and the neuropeptides allatostatin 7, allatotropin, corazonin, gastrin/cholecystokinin, FMRFamide, leucokinin I, and pigment-dispersing hormone. Some of the immunostained neurons appear to be local neurons of the accessory medulla, whereas others connect this neuropil to various brain areas, including the lamina, the contralateral optic lobe, the posterior optic tubercles, and the superior protocerebrum. Double-label experiments show the colocalization of immunoreactivity against pigment-dispersing hormone with compounds related to FMRFamide, serotonin, and leucokinin I. The neuronal and neurochemical organization of the accessory medulla is consistent with the current hypothesis for a role of this brain area as a circadian pacemaking center in the insect brain.
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    URL: http://dx.doi.org/10.1007/BF00319128
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    Ontogenetic development of neuropeptide Y-like-immunoreactive cells in the gastroenteropancreatic endocrine system of the dogfish (1995)
    Springer
    Cell & tissue research 282 (1995), S. 33-40 
    Details
    ISSN: 1432-0878
    Keywords: Neuropeptide Y ; Gastroenteropancreatic (GEP) endocrine system ; Development, ontogenetic ; Vitellointestinal duct ; Pancreas, exocrine ; Pancreas, endocrine ; Immunocytochemistry ; Scyliorhinus torazame (Elasmobranchii)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract This immunocytochemical study was carried out to elucidate the ontogenetic development of neuropeptide Y-like-immunoreactive cells in the gastroenteropancreatic endocrine system of the cloudy dogfish, Scyliorhinus torazame. Immunostained cells first appeared in the pancreas of the embryo at the 15-mm stage, and were also detected in the vitellointestinal duct of the yolk stalk at the 20-mm stage. These cells were polymorphic, with occasional processes that were sometimes directed toward the vascular wall or into the cavity of the vitellointestinal duct. At the 34-mm stage, immunostained cells could also be found in the proximal part of the spiral intestine and, by the 74-mm stage, immunopositive cells were present in the gastric mucosa. In the gut and pancreas, the cells gradually increased in number with development, whereas in the vitellointestinal duct and internal yolk sac, they decreased and seemed to disappear following hatching. Thus, in juveniles, the distribution of the neuropeptide Y-like-immunoreactive cells in the gastroenteropancreatic endocrine system had attained that of adults. Electron-microscopic immunocytochemistry demonstrated that, in the labeled cells of the vitellointestinal duct, the neuropeptide Y-like antigen was located in cytoplasmic granules, as in the cells of the gut and pancreas.
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    URL: http://dx.doi.org/10.1007/BF00319130
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    Immunocytochemical characterization of the accessory medulla in the cockroach Leucophaea maderae (1995)
    Springer
    Cell & tissue research 282 (1995), S. 3-19 
    Details
    ISSN: 1432-0878
    Keywords: Key words: Circadian rhythm ; Colocalization ; Immunocytochemistry ; Brain (CNS) ; invertebrate ; Optic lobe ; Pigment-dispersing hormone ; insect ; Leucophaea maderae (Insecta)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. Several lines of evidence suggest that pigment-dispersing hormone-immunoreactive neurons with ramifications in the accessory medulla are involved in the circadian system of insects. The present study provides a detailed analysis of the anatomical and neurochemical organization of the accessory medulla in the brain of the cockroach Leucophaea maderae. We show that the accessory medulla is compartmentalized into central dense nodular neuropil surrounded by a shell of coarse fibers. It is innervated by neurons immunoreactive to antisera against serotonin and the neuropeptides allatostatin 7, allatotropin, corazonin, gastrin/cholecystokinin, FMRFamide, leucokinin I, and pigment-dispersing hormone. Some of the immunostained neurons appear to be local neurons of the accessory medulla, whereas others connect this neuropil to various brain areas, including the lamina, the contralateral optic lobe, the posterior optic tubercles, and the superior protocerebrum. Double-label experiments show the colocalization of immunoreactivity against pigment-dispersing hormone with compounds related to FMRFamide, serotonin, and leucokinin I. The neuronal and neurochemical organization of the accessory medulla is consistent with the current hypothesis for a role of this brain area as a circadian pacemaking center in the insect brain.
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    URL: http://dx.doi.org/10.1007/s004410050454
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    Immunocytochemical localisation of some lysosomal hydrolases, their presence in luminal fluid and their directional secretion by human epididymal cells in culture (1995)
    Springer
    Cell & tissue research 280 (1995), S. 415-425 
    Details
    ISSN: 1432-0878
    Keywords: Epididymis ; Efferent ducts ; Cell culture ; Immunocytochemistry ; Immunoprecipitation ; Man
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The way in which the human epididymis modifies spermatozoa during their sojourn in this structure might be clarified by knowledge of the nature of its secretions. We have examined the presence of several lysosomal hydrolases in human epididymal tissue and fluids, and their synthesis and secretion by monolayer cultures. Tissues were obtained from men undergoing orchidectomy for prostatic carcinoma. The enzymes cathepsin D and acid α-glucosidase were localised in the lysosomes of epithelial cells from the corpus epididymidis, by an immunocytochemical technique. Cathepsin D was also found in epithelial cells of the efferent ducts within lysosomes, apical vesicles and multivesicular bodies. No immunolocalisation of acid glucosidase in the efferent ducts or on the microvilli of the corpus was demonstrable. Cathepsin D, β-hexosaminidase (N-acetylglucosaminidase) and α-glucosidase were measurable in the luminal fluid from the human corpus epididymidis; β-hexosaminidase was secreted into the culture medium by confluent monolayers of epididymal and efferent duct cells. Immunoprecipitation of cell extracts and culture medium of these cultures incubated with 35S-methionine revealed that the precursors of cathepsin D and β-hexosaminidase were synthesized and secreted by such monolayers. Thus, active lytic enzymes are secreted by the human epididymis and could modify sperm membranes.
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    URL: http://dx.doi.org/10.1007/BF00307815
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    Presence of embryonic myosin in normal postural muscles of the adult rat (1995)
    Springer
    Cell & tissue research 280 (1995), S. 541-548 
    Details
    ISSN: 1432-0878
    Keywords: Musle, striated, skeletal ; Regeneration ; Myosin ; Immunocytochemistry ; Rat (Sprague Dawley)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Indirect immunofluorescence was used to localize embryonic myosin heavy chains in soleus, adductor longus, tibialis anterior, plantaris, and extensor digitorum longus muscles of 6-month-old rats. A monoclonal antibody (2B6), specifically recognizing rat embryonic myosin, was applied to unfixed, transverse, frozen sections. The number of embryonic myosin-positive (EMP) extrafusal fibers was expressed as a percentage of the total number of fibers. EMP extrafusal fibers were only seen in the soleus and adductor longus muscles, both postural muscles. Approximately 1% of the soleus muscle fibers appeared positively stained for embryonic myosin. The majority of such fibers had a small diameter (〈500 ν), appeared intensely fluorescent, and typically contained central nuclei. Re-expression of embryonic myosin due to spontaneous fiber denervation is not a likely factor in this study, since alpha-bungarotoxin and N-CAM localization were restricted to the motor end-plate region of EMP fibers. Since embryonic myosin was shown to disappear in all normal-sized myofibers by 2 to 3 months of age, the results suggest that the EMP extrafusal fibers seen in postural muscles of 6 to 12-month-old animals are regenerating myofibers. We speculate that a small number of muscle fibers may be regenerating in normal, adult postural muscles, in response to fiber damage possibly caused by excessive recruitment or overloading.
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    URL: http://dx.doi.org/10.1007/BF00318358
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    Sources of inputs to longitudinal muscle motor neurons and ascending interneurons in the guinea-pig small intestine (1995)
    Springer
    Cell & tissue research 280 (1995), S. 549-560 
    Details
    ISSN: 1432-0878
    Keywords: Enteric nervous system ; Immunocytochemistry ; Calretinin ; Calbindin ; Bombesin ; Small intestine ; Guinea-pig
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Light- and electron-microscopic studies were used to investigate connections between specific subgroups of neurons in the myenteric plexus of the guineapig small intestine. Inputs to two classes of calretinin-immunoreactive (IR) nerve cells, longitudinal muscle motor neurons and ascending interneurons, were examined. Inputs from calbindin-IR primary sensory neurons and from three classes of descending interneurons were studied. Electron-microscopic analysis showed that calbindin-IR axons formed two types of inputs, synapses and close contacts, on calretinin-IR neurons. About 40% of inputs to the longitudinal muscle motor neurons and 70% to ascending interneurons were calbindin-IR. Approximately 50% of longitudinal muscle motor neurons were surrounded by bombesin-IR dense pericellular baskets and 40% by closely apposed varicosities. At the electron-microscope level, the bombesin-IR varicosities were found to form synapses and close contacts with the motor neurons. Dense pericellular baskets with bombesin-IR surrounded 36% of all ascending interneurons, and a further 17% had closely apposed varicosities. Somatostatin-and 5-HT-IR descending interneurons provided no dense pericellular baskets to calretinin-IR nerve cells. Thus, calretinin-IR, longitudinal muscle motor neurons and ascending interneurons receive direct synaptic inputs from intrinsic primary sensory neurons and from non-cholinergic, bombesin-IR, descending interneurons.
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    URL: http://dx.doi.org/10.1007/BF00318359
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    Localization of the 110 kDa receptor for laminin in brains of embryonic and postnatal mice (1995)
    Springer
    Cell & tissue research 279 (1995), S. 371-377 
    Details
    ISSN: 1432-0878
    Keywords: Laminin ; Nerve tracts ; Ontogenetic development ; Brain ; Immunocytochemistry ; Mouse
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Laminin, a large glycoprotein of the basement membrane that promotes the growth of nerve cell processes in vitro has also been detected in the brains of developing embryos in situ where it is postulated to promote or guide neural outgrowth. We have investigated the histological and developmental patterns of a receptor to a specific pentapeptide sequence in the A chain of the laminin molecule (PA22-2 or IKVAV) that has been identified as a neuron growth-promoting sequence. Standard immunocytochemical procedures were used to localize the receptor by means of a polyclonal antibody to affinity-purified receptor (MR=110 kDa) from mouse brains. Results for postnatal stages (P) stages (P 1,7,8,25,30,and adult) show that the 110 kDa receptor is localized in fibers in the cortex and hippocampus, in astroglial cells at the surface of the cortex, and in neuronal cell bodies in the hippocampus. In contrast, the A-chain ligand is localized in cell bodies in the same regions at P stages. For embryonic stages (E) (E 14 and E 16) the receptor is localized in bundles of fibers in the superficial and deep cortical layers, and in cell bodies in these regions at E 14 only. Staining for the A chain ligand of the receptor was first seen postnatally. We speculate that the inverse histological pattern of receptor and ligand with respect to cell bodies and fibers may reflect a role in controlling axon guidance during development or repair during regeneration.
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    URL: http://dx.doi.org/10.1007/BF00318494
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    The distribution of neurones immunoreactive for β-tyrosine hydroxylase, dopamine and serotonin in the ventral nerve cord of the cricket, Gryllus bimaculatus (1995)
    Springer
    Cell & tissue research 280 (1995), S. 583-604 
    Details
    ISSN: 1432-0878
    Keywords: Dopamine ; Serotonin ; Tyrosine hydroxylase ; Immunocytochemistry ; Nervous system, insect-Gryllus bimaculatus (Insecta)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The cellular localization of the biogenic amines dopamine and serotonin was investigated in the ventral nerve cord of the cricket, Gryllus bimaculatus, using antisera raised against dopamine, β-tyrosine hydroxylase and serotonin. Dopamine-(n〈-70) and serotonin-immunoreactive (n〈-120) neurones showed a segmental arrangement in the ventral nerve cord. Some neuromeres, however, did not contain dopamine-immunoreactive cell bodies. The small number of stained cells allowed complete identification of brain and thoracic cells, including intersegmentally projecting axons and terminal arborizations. Dopamine-like immunostaining was found primarily in plurisegmental interneurones with axons descending to the soma-ipsilateral hemispheres of the thoracic and abdominal ganglia. In contrast, serotonin-immunostaining occurred predominantly in interneurones projecting via soma-contralaterally ascending axons to the thorax and brain. In addition, serotonin-immunoreactivity was also present in efferent cells and afferent elements. Serotonin-immunoreactive, but no dopamine-immunoreactive, varicose fibres were observed on the surface of some peripheral nerves. Varicose endings of both dopamine-and serotonin-immunoreactive neurones occurred in each neuromere and showed overlapping neuropilar projections in dorsal and medial regions of the thoracic ganglia. Ventral associative neuropiles lacked dopamine-like immunostaining but were innervated by serotonin-immunoreactive elements. A colocalization of the two amines was not observed. The topographic representation of neurone types immunoreactive for serotonin and dopamine is discussed with respect to possible modulatory functions of these biogenic amines in the central nervous system of the cricket.
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    URL: http://dx.doi.org/10.1007/BF00318362
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    Specific immunocytochemical localization of cathepsin E at the ruffled border membrane of active osteoclasts (1995)
    Springer
    Cell & tissue research 281 (1995), S. 85-91 
    Details
    ISSN: 1432-0878
    Keywords: Cathepsin E ; Aspartic proteinase ; Osteoclasts ; Immunocytochemistry ; Rat (WKA)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The immunocytochemical localization of cathepsin E, a non-lysosomal aspartic proteinase, was investigated in rat osteoclasts using the monospecific antibody to this protein. At the light-microscopic level, the preferential immunoreactivity for cathepsin E was found at high levels in active osteoclasts in the physiological bone modeling process. Neighboring osteoblastic cells were devoid of its immunoreactivity. At the electron-microscopic level, cathepsin E was exclusively confined to the apical plasma membrane at the ruffled border of active osteoclasts and the eroded bone surface. Cathepsin E was also concentrated in some endocytotic vacuoles of various sizes in the vicinity of the ruffled border membrane, some of which appeared to be secondary lysosomes containing the phagocytosed materials. These results strongly suggest that this enzyme is involved both in the extracellular degradation of the bone organic matrix and in the intracellular breakdown of the ingested substances in osteoclasts.
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    URL: http://dx.doi.org/10.1007/BF00307961
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    Localization of the 110 kDa receptor for laminin in brains of embryonic and postnatal mice (1995)
    Springer
    Cell & tissue research 279 (1995), S. 371-377 
    Details
    ISSN: 1432-0878
    Keywords: Key words: Laminin ; Nerve tracts ; Ontogenetic development ; Brain ; Immunocytochemistry ; Mouse
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. Laminin, a large glycoprotein of the basement membrane that promotes the growth of nerve cell processes in vitro has also been detected in the brains of developing embryos in situ where it is postulated to promote or guide neural outgrowth. We have investigated the histological and developmental patterns of a receptor to a specific pentapeptide sequence in the A chain of the laminin molecule (PA22-2 or IKVAV) that has been identified as a neuron growth-promoting sequence. Standard immunocytochemical procedures were used to localize the receptor by means of a polyclonal antibody to affinity-purified receptor (MR=110 kDa) from mouse brains. Results for postnatal stages (P) stages (P 1,7,8,25,30,and adult) show that the 110 kDa receptor is localized in fibers in the cortex and hippocampus, in astroglial cells at the surface of the cortex, and in neuronal cell bodies in the hippocampus. In contrast, the A-chain ligand is localized in cell bodies in the same regions at P stages. For embryonic stages (E) (E 14 and E 16) the receptor is localized in bundles of fibers in the superficial and deep cortical layers, and in cell bodies in these regions at E 14 only. Staining for the A chain ligand of the receptor was first seen postnatally. We speculate that the inverse histological pattern of receptor and ligand with respect to cell bodies and fibers may reflect a role in controlling axon guidance during development or repair during regeneration.
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    URL: http://dx.doi.org/10.1007/s004410050293
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    Regeneration and post-metamorphic development of the central nervous system in the protochordate Ciona intestinalis: a study with monoclonal antibodies (1995)
    Springer
    Cell & tissue research 279 (1995), S. 421-432 
    Details
    ISSN: 1432-0878
    Keywords: Key words: Trans-differentiation ; Proliferation ; Bromodeoxyuridine ; Immunocytochemistry ; Regeneration ; Ciona intestinalis (Tunicata)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. In this study, we use three monoclonal antibodies that recognise antigens present in the central nervous system of the ascidian Ciona intestinalis to study regeneration and post-metamorphic development of the neural ganglion. We have also used bromodeoxyuridine labelling to study generation of the neuronal precursor cells. The first antibody, CiN 1, recognises all neurones in the ganglion, whereas the second, CiN 2, recognises only a subpopulation of the large cortical neurones. Western blotting studies show that CiN 2 recognises two membrane-bound glycoproteins of apparent Mr 129 and 100 kDa. CiN 1 is not reactive on Western blots. Immunocytochemical studies with these antibodies show that CiN 1-immunoreactive neurone-like cells are present at the site of regeneration as early as 5–7 days post-ablation, a sub-population of CiN 2-immunoreactive cells being detected by 9–12 days post-ablation. The third antibody, ECM 1, stains extracellular matrix components and recognises two diffuse bands on Western blots of whole-body and ganglion homogenates. The temporal and spatial pattern of appearance of CiN 1 and CiN 2 immunoreactivity both during post-metamorphic development and in regeneration occurs in the same sequence in both processes. Studies with bromodeoxyuridine show labelled nuclei in some neurones in the regenerating ganglion. Plausibly these originate from the dorsal strand, an epithelial tube that reforms by cell proliferation during the initial phases of regeneration. A second population of cells, the large cortical neurones, do not incorporate bromodeoxyuridine and thus must have been born prior to the onset of regeneration. This latter finding indicates a mechanism involving trans-differentiation of other cell types or differentiation of long-lived totipotent stem cells.
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    URL: http://dx.doi.org/10.1007/s004410050299
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    Localization of choline acetyltransferase-expressing neurons in the larval visual system of Drosophila melanogaster (1995)
    Springer
    Cell & tissue research 282 (1995), S. 193-202 
    Details
    ISSN: 1432-0878
    Keywords: Key words: Choline acetyltransferase ; Cholinergic neuron ; Visual system ; Bolwig’s organ ; Immunocytochemistry ; In situ hybridization ; Drosophila melanogaster (Insecta)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. Choline acetyltransferase (ChAT) is the enzyme catalyzing the biosynthesis of acetylcholine and is considered to be a phenotypically specific marker for cholinergic neurons. We have examined the distribution of ChAT-expressing neurons in the larval nervous system of Drosophila melanogaster by three different but complementary techniques: in situ hybridization with a cRNA probe to ChAT messenger RNA, immunocytochemistry using a monoclonal anti-ChAT antibody, and X-gal staining of transformed animals carrying a reporter gene composed of 7.4  kb of 5′ flanking DNA from the ChAT gene fused to a lacZ reporter gene. All three techniques demonstrated ChAT-expressing neurons in the larval visual system. In embryos, the photoreceptor organ (Bolwig’s organ) exhibited strong cRNA hybridization signals. The optic lobe of late third-instar larvae displayed ChAT immunoreactivity in Bolwig’s nerve and a neuron close to the insertion site of the optic stalk. This neuron’s axon ran in parallel with Bolwig’s nerve to the larval optic neuropil. This neuron is likely to be a first-order interneuron of the larval visual system. Expression of the lacZ reporter gene was also detected in Bolwig’s organ and the neuron stained by anti-ChAT antibody. Our observations indicate that acetylcholine may be a neurotransmitter in the larval photoreceptor cells as well as in a first-order interneuron in the larval visual system of Drosophila melanogaster.
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    URL: http://dx.doi.org/10.1007/s004410050472
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    Origin and destination of globules and irregular masses in the gonadotropin cells from the pituitary of the African catfish, Clarias gariepinus: a morphological study (1995)
    Springer
    Cell & tissue research 280 (1995), S. 113-122 
    Details
    ISSN: 1432-0878
    Keywords: Pituitary ; Gonadotrops ; Crinophagy ; Electron microscopy ; Enzyme cytochemistry ; Immunocytochemistry ; Autoradiography ; Catfish, Clarias gariepinus (Teleostei)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The possible function of globules and irregular membrane-bound masses in the gonadotropin cells of the pituitary of Clarias gariepinus was studied. Strong secretory stimulation led to the disappearance of the secretory granules from gonadotropin cells but globules and irregular masses remained present. Acid phosphatase was detected enzyme-cytochemically in both globules and irregular masses. Radiolabelling with tritiated amino acids followed by autoradiography demonstrated that globules received radioactive material after secretory granules. The latter received radioactive material within 75 min of administration of radioactive amino acids but globules and irregular masses did not. Although some globules became radioactively labelled within 24 h of the administration of radioactive amino acids, irregular masses remained unlabelled during this period. Secretory granules reacted positively with antisera against α and β gonadotropin subunits, whereas globules and irregular masses only reacted with the antiserum against the β subunit. A moderate anti-7B2 immunoreactivity was demonstrated in secretory granules and globules, whereas irregular masses labelled strongly. The combined cytological results indicate that globules and irregular masses are degradative, possibly crinophagic structures which develop by fusional events from secretory granules to globules and then to irregular masses.
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    URL: http://dx.doi.org/10.1007/BF00304516
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    Immunolocalization of interleukin-1α in rat mandibular molars and its enhancement after in vivo injection of epidermal growth factor (1995)
    Springer
    Cell & tissue research 280 (1995), S. 21-26 
    Details
    ISSN: 1432-0878
    Keywords: Key words: Interleukin ; Stellate reticulum ; Immunocytochemistry ; Epidermal growth factor ; Interleukin-1 receptor type I messenger RNA ; Tooth eruption ; Rat (Sprague Dawley)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. Immunolocalization of interleukin-1α in the first mandibular molars of rats from day 0–12 postnatally showed that the protein was localized in the epithelial stellate reticulum adjacent to the dental follicle. Staining of the stellate reticulum was most prominent in the early days postnatally and was absent by postnatal day 11. Injection of epidermal growth factor into rats at day 0 greatly increased the intensity of the staining for interleukin-1α in the stellate reticulum. Epidermal growth factor (EGF) enhanced the gene expression of interleukin-1α in stellate reticulum cells in vitro, and this study suggests there is enhanced translation of interleukin-1α messenger RNA in the stellate reticulum following EGF injection. In turn, the interleukin-1α may exert its effect on the dental follicle cells adjacent to the stellate reticulum because EGF also enhanced expression of the interleukin-1 receptor type I messenger RNA in cultured dental follicle cells as well as enhancing its expression in vivo. In view of the fact that injection of EGF will stimulate precocious eruption of teeth, its stimulus of interleukin-1α synthesis in the stellate reticulum may be the mechanism by which EGF initiates a cascade of molecular events to signal the onset of tooth eruption.
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    URL: http://dx.doi.org/10.1007/BF00304507
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    Characterization and localization of an Mr 225 kDa polypeptide specifically involved in the defence mechanisms of the clam Tapes semidecussatus (1995)
    Springer
    Cell & tissue research 280 (1995), S. 27-37 
    Details
    ISSN: 1432-0878
    Keywords: Key words: Defence mechanisms ; Encapsulation ; Granulocytes ; Immunocytochemistry ; Parasitism ; Perkinsus sp. (Protozoa) ; Tapes semidecussatus (Mollusca
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. Parasitosis by the trophozoite protozoan Perkinsus sp. (Apicomplexa, Perkinsea) induces in the gill filaments of the clam Tapes semidecussatus (Mollusca, Bivalvia) a cellular reaction, which is constituted by infiltrated granulocytes. This cellular reaction has characteristics of those of a holocrine gland, since the parasites are encapsulated by the secretion product of the granulocytes after cell death. An enriched fraction of prezoosporangia and their ass ociated capsule was obtained after culture of the parasitized gills in fluid thioglycollate medium. Specific polypeptides from this fraction were separated by SDS-PAGE and isolated for rabbit immunizations. The serum obtained against an Mr 225 kDa polypeptide, revealed its exclusive localization in the capsule and in the granules of the infiltrated granulocytes, thus indicating that this polypeptide is synthesized by these cells and secreted, in a polarized way, around the trophozoites resulting in t heir encapsulation. Selective deglycosylation of the polypeptide, by Endo H and alkaline β-elimination, did not show an effect on its molecular weight or antibody recognition. Furthermore, the absence of the 225 kDa band in the Western-blots of non-parasitized gills indicated the specific association of this polypeptide with the parasitosis. Finally, this is the first tissue-specific factor described in molluscs in relation to defence mechanisms.
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    URL: http://dx.doi.org/10.1007/BF00304508
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    Origin and destination of globules and irregular masses in the gonadotropin cells from the pituitary of the African catfish, Clarias gariepinus:a morphological study (1995)
    Springer
    Cell & tissue research 280 (1995), S. 113-122 
    Details
    ISSN: 1432-0878
    Keywords: Key words: Pituitary ; Gonadotrops ; Crinophagy ; Electron microscopy ; Enzyme cytochemistry ; Immunocytochemistry ; Autoradiography ; Catfish ; Clarias gariepinus (Teleostei)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. The possible function of globules and irregular membrane-bound masses in the gonadotropin cells of the pituitary of Clarias gariepinus was studied. Strong secretory stimulation led to the disappearance of the secretory granules from gonadotropin cells but globules and irregular masses remained present. Acid phosphatase was detected enzyme-cytochemically in both globules and irregular masses. Radiolabelling with tritiated amino acids followed by autoradiography demons trated that globules received radioactive material after secretory granules. The latter received radioactive material within 75 min of administration of radioactive amino acids but globules and irregular masses did not. Although some globules became radioactively labelled within 24 h of the administration of radioactive amino acids, irregular masses remained unlabelled during this period. Secretory granules reacted positively with antisera against α and β gonadotropin subunits, whereas globules and irregular masses only reacted with the antiserum against the β subunit. A moderate anti-7B2 immunoreactivity was demonstrated in secretory granules and globules, whereas irregular masses labelled strongly. The combined cytological results indicate that globules and irregular masses are degradative, possibly crinophagic structures which develop by fusional events from secretory granules to globules and then to irregular masses.
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    URL: http://dx.doi.org/10.1007/BF00304516
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    Development of melanin-concentrating hormone-immunoreactive elements in the brain of gilthead seabream (Sparus auratus) (1995)
    Springer
    Cell & tissue research 282 (1995), S. 523-526 
    Details
    ISSN: 1432-0878
    Keywords: Melanin-concentrating hormone ; Immunocytochemistry ; Development, ontogenetic ; Sparus auratus (Teleostei)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The development of the hypothalamic melanin-concentrating hormone (MCH) system of the teleost Sparus auratus has been studied by immunocytochemistry using an anti-salmon MCH serum. Immunoreactive perikarya and fibers are found in embryos, larvae, and juvenile specimens. In juveniles, most labeled neurons are present in the nucleus lateralis tuberis; some are dispersed in the nucleus recessus lateralis and nucleus periventricularis posterior. From the nucleus lateralis tuberis, MCH neurons project a conspicuous tract of fibers to the ventral hypothalamus; this penetrates the pituitary stalk and reaches the neurohypophysis. Most fibers end close to the cells of the pars intermedia, and some reach the adenohypophysial rostral pars distalis. Immunoreactive fibers can also be seen in extrahypophysial localizations, such as the preoptic region and the nucleus sacci vasculosi. In embryos, MCH-immunoreactive neurons first appear at 36 h post-fertilization in the ventrolateral margin of the developing hypothalamus. In larvae, at 4 days post-hatching, perikarya can be observed in the ventrolateral border of the hypothalamus and in the mid-hypothalamus, near the ventricle. At 26 days post-hatching, MCH perikarya are restricted to the nucleus lateralis tuberis. The neurohypophysis possesses MCH-immunoreactive fibers from the second day post-hatching. The results indicate that MCH plays a role in larval development with respect to skin melanophores and cells that secrete melanocyte-stimulating hormone.
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    URL: http://dx.doi.org/10.1007/BF00318885
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    5′-Nucleotidase in PC12 cells as revealed by immunocytochemistry (1995)
    Springer
    Cell & tissue research 280 (1995), S. 123-131 
    Details
    ISSN: 1432-0878
    Keywords: Differentiation ; 5′-Nucleotidase ; Immunocytochemistry ; PC12 cells ; Synaptophysin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract 5′-Nucleotidase hydrolyzes 5′-mononucleotides to their nucleosides but is also thought to have a function in neuronal differentiation and synapse formation. The distribution of the enzyme, a glycosyl-phosphatidylinositol-anchored sialoglycoprotein, was investigated in PC12 cells using immunofluorescence microscopy. 5′-Nucleotidase was located both in intracellular compartments and at the cell surface. There was no principal difference in the cellular distribution between undifferentiated cells and after neuritogenic differentiation by nerve growth factor. Intracellularly, 5′-nucleotidase often revealed a sickle-shaped perinuclear distribution and a dotted pattern throughout the cytoplasm, including that of neurites and growth cones. The intracellular distribution was clearly different from that of the synaptic vesicle protein synaptophysin. However, the dotted fluorescence resembled that obtained after uptake of the endosomal marker acridine orange. 5′-Nucleotidase was present on the entire cell surface including all neurites formed after differentiation. There was no increase in 5′-nucleotidase fluorescence at synapse-like contacts between the tips of neurites and other PC12 cells. Surfacelocated 5′-nucleotidase could no longer be detected after the application of glycosyl-phosphatidylinositol-specific phospholipase C to cultured cells. This treatment did not affect PC12 cell differentiation. Our results thus reveal 5′-nucleotidase both at the surface and within organelles and suggest that PC12 cells may be used as a model system for the study of the physiological function of 5′-nucleotidase in neural cells.
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    URL: http://dx.doi.org/10.1007/BF00304517
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    5′-Nucleotidase in PC12 cells as revealed by immunocytochemistry (1995)
    Springer
    Cell & tissue research 280 (1995), S. 123-131 
    Details
    ISSN: 1432-0878
    Keywords: Key words: Differentiation ; 5′-Nucleotidase ; Immunocytochemistry ; PC12 cells ; Synaptophysin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. 5′-Nucleotidase hydrolyzes 5′-mononucleotides to their nucleosides but is also thought to have a function in neuronal differentiation and synapse formation. The distribution of the enzyme, a glycosyl-phosphatidylinositol-anchored sialoglycoprotein, was investigated in PC12 cells using immunofluorescence microscopy. 5′-Nucleotidase was located both in intracellular compartments and at the cell surface. There was no principal difference in the cellular distrib ution between undifferentiated cells and after neuritogenic differentiation by nerve growth factor. Intracellularly, 5′-nucleotidase often revealed a sickle-shaped perinuclear distribution and a dotted pattern throughout the cytoplasm, including that of neurites and growth cones. The intracellular distribution was clearly different from that of the synaptic vesicle protein synaptophysin. However, the dotted fluorescence resembled that obtained after uptake of the endosomal marker acridine orange. 5′-Nucleotidase was present on the entire cell surface including all neurites formed after differentiation. There was no increase in 5′-nucleotidase fluorescence at synapse-like contacts between the tips of neurites and other PC12 cells. Surface-located 5′-nucleotidase could no longer be detected after the application of glycosyl-phosphatidylinositol-specific phospholipase C to cultured cells. This treatment did not affect PC12 cell differentiation. Our results thus reveal 5′ -nucleotidase both at the surface and within organelles and suggest that PC12 cells may be used as a model system for the study of the physiological function of 5′-nucleotidase in neural cells.
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    Secretory glycoproteins of the subcommissural organ of the dogfish (Scyliorhinus canicula): evidence for the existence of precursor and processed forms (1995)
    Springer
    Cell & tissue research 283 (1995), S. 75-84 
    Details
    ISSN: 1432-0878
    Keywords: Key words: Subcommissural organ ; Secretory glycoproteins ; Antibodies ; Immunochemistry ; Immunocytochemistry ; Dogfish ; Scyliorhinus canicula (Elasmobranchii)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. The subcommissural organ of the dogfish, Scyliorhinus canicula (L), has been investigated by use of antibodies and lectins applied to blots and tissue sections processed for light and electron microscopy. Antibodies have been raised against each of the bands that have previously been identified in immunoblots by the use of antisera raised against secretory glycoproteins extracted from the dogfish subcommissural organ, viz., the 600-kDa band and two gel regions including the 475 to 400-kDa and the 145-kDa bands obtained from preparative gels; they are referred to as Ab-600, Ab-475/400, and Ab-145. These antisera and the lectins concanavalin A and wheat germ agglutinin have been used for the staining of: (1) blots of extracts of the dogfish subcommissural organ and optic tectum; (2) tissue sections of the dogfish brain. The findings indicate that the bands of 600, 475 and 400 kDa contain compounds that should be regarded as secretory glycoproteins of the dogfish subcommissural organ. The 600-kDa and 400-kDa bands are labeled by concanavalin A; wheat germ agglutinin labels the 475-kDa band strongly and the other two weakly. Ab-600 reacts with the bands at 600, 475 and 400 kDa and stains materials stored in the rough endoplasmic reticulum and secretory granules of 200–600 nm in diameter. The 600-kDa compound is probably a precursor form. Ab-475/400 stains the same three bands revealed by Ab-600; immunocytochemically, it reacts with two types of secretory granules (200–600 and 800–1200 nm in diameter) but it does not label the rough endoplasmic reticulum. Ab-145 reveals the bands at 600, 475 and 400 kDa and a diffuse zone in the region of 145 kDa; in light-microscopic immunocytochemistry, it behaves as Ab-475/400. The 475-kDa and 400-kDa glycoproteins, and a compound of approximately 145 kDa thus probably correspond to processed forms. Ab-475/400 stains granules present in cell processes ending on local blood vessels and at the leptomeninges. Since this antiserum selectively labels secretory granules, this finding may be taken as evidence for a basal route of secretion.
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    Presence of sauvagine-like epitopes in the interrenal gland of the bullfrog Rana catesbeiana (1995)
    Springer
    Cell & tissue research 283 (1995), S. 117-123 
    Details
    ISSN: 1432-0878
    Keywords: Key words: Sauvagine ; Corticotropin-releasing factor ; Immunocytochemistry ; Interrenal gland ; Rana catesbeiana (Anura)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. Immunocytochemistry was used to investigate the presence of corticotropin-releasing factor-like peptides in the interrenal (adrenal) glands of the bullfrog Rana catesbeiana by using specific antisera raised against synthetic nonconjugated rat/human corticotropin-releasing factor, urotensin I, and sauvagine. From these three antisera, covering a broad range of corticotropin-releasing factor-like immunoreactivities, only the sauvagine antiserum gave positive immunoreactivity. Sauvagine immunoreactivity was found in cortical cells grouped into cords in the renal zone of the interrenal gland. The central and subcapsular cords were less stained. Tyrosine hydroxylase-positive chromaffin cells were not sauvagine-immunoreactive. The immunoreactivity was abolished, in all cases, by previous immunoabsorption of the sauvagine antiserum with synthetic sauvagine (0.1 μM), but it was not eliminated by sucker (Catostomus commersoni) urotensin I, sole (Hippoglossoides elassodon) urotensin I, sucker corticotropin-releasing factor, rat/human corticotropin-releasing factor, or ovine corticotropin-releasing factor (0.1–10 μM). In a sauvagine radioimmunoassay, interrenal extracts displaced 125I-sauvagine from antiserum only partially, and not in parallel with the sauvagine standard curve. The results suggest that the sauvagine immunoreactivity in the R. catesbeiana interrenal gland may represent a novel sauvagine-like peptide.
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    URL: http://dx.doi.org/10.1007/s004410050519
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    Immunocytochemical and morphometric study on the changes of TSH, PRL, GH and ACTH cells during the development of Bufo arenarum (1995)
    Springer
    Cell & tissue research 283 (1995), S. 125-132 
    Details
    ISSN: 1432-0878
    Keywords: Key words: Pituitary hormones ; Immunocytochemistry ; Morphometry ; Metamorphosis ; Bufo arenarum (Anura)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. The development and dynamics of thyrotropin (TSH), adrenocorticotropic hormone (ACTH), prolactin (PRL), and growth hormone (GH) cells have been studied using immunocytochemical techniques and rabbit antisera, raised against the relevant human hormone, in the pars distalis of Bufo arenarum larvae at different stages of development. The four types of cells studied were identified in different zones of the pars distalis: TSH cells occurred mainly in the centro-ventral zone, ACTH cells in the rostral and dorsal zones, GH cells in the central and caudal zones, and PRL cells in the anterior two-thirds of the gland. This distribution pattern does not show significant changes with development. Morphometry and stereology were used to evaluate the changes observed in the volume of the pars distalis and the immunoreactive cells during development. The former increased during larval growth and decreased throughout the metamorphic climax. The results obtained on cell number, volume density, and total volume suggest that, during larval growth (pre-prometamorphosis) of B. arenarum, TSH, PRL, GH and ACTH cells show a proliferative period with storage of their hormones; a second period involving hormone release occurs at the metamorphic climax.
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    URL: http://dx.doi.org/10.1007/s004410050520
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    Ultrastructural distribution of endogenous immunoglobulin-G in human term amniochorion (1995)
    Springer
    Cell & tissue research 281 (1995), S. 367-374 
    Details
    ISSN: 1432-0878
    Keywords: Placenta ; Amniochorion ; Cytotrophoblast cells ; Immunoglobulin G ; Immunocytochemistry ; Human
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Maternal immunoglobulin-G (IgG) is known to be transported across the placental syncytiotrophoblast during the period when the human fetus is incapable of manufacturing these defensive molecules. In this study we investigated the possible role of the amniochorion, that surrounds the amniotic cavity in which the fetus lies, in the transfer of immunoglobulin. Endogenous IgG was localised in the amniochorion by confocal immunofluorescence microscopy and by ultrastructural labelling of ultrathin frozen tissue sections using the protein A-gold technique. Immunoreactivity was identified in the extracellular matrix tissues and necrotic amniotic epithelial cells. Healthy amniotic epithelial cells and cytotrophoblast cells of the chorion laeve were devoid o endogenous IgG. These results suggest a possible non-specific paracellular transport pathway between cytotrophoblast cells, which may conceivably contribute to the acquisition of passive immunity by the fetus, and offer a rational explanation for the presence of small quantities of maternal IgG in the amniotic fluid.
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    URL: http://dx.doi.org/10.1007/BF00583405
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    Unusual distribution of tubulin isoforms in the snail Lymnaea stagnalis (1995)
    Springer
    Cell & tissue research 281 (1995), S. 507-515 
    Details
    ISSN: 1432-0878
    Keywords: Key words: Microtubules ; Isoforms ; Nervous system ; Locomotion ; Cilia ; Immunocytochemistry ; Western blotting ; Lymnaea stagnalis (Mollusca)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. Immunocytochemistry and Western blotting techniques demonstrated that the nervous system and foot of the pond snail Lymnaea stagnalis are rich sources of tubulin, which can be extracted and assembled in vi- tro in the presence of taxol. Various broad-spectrum antibodies raised against α-tubulin and β-tubulin yielded qualitatively similar results. One monoclonal antibody to trypanosome α−tubulin, however, labelled α-tubulin more strongly on both probed sections and Western blots. Cytochemistry and immunoblotting revealed that tyrosinated tubulin constitutes a large proportion of total α-tubulin in locomotor cilia of the foot and in axons of the nervous system. Detyrosinated tubulin also appeared to be abundant in the foot cilia but only a very faint band of detyrosinated tubulin was found on protein blots extracted from the central ganglia, and staining was barely detectable in central ganglia or peripheral nerves. Similarly, acetylated tubulin appeared to be abundant in foot cilia, but Western blotting indicated only low levels of acetylated tubulin in the nervous system. Immunocytochemistry indicated that, while most neurons possessed little or no acetylated tubulin, a small number of axons contained significant amounts of this isoform. Thus, while a large amount of tubulin was expected in the nervous system and locomotor cilia of L. stagnalis, the observed distribution of isoforms was unanticipated. Specifically, neurons of other organisms have generally been reported to contain substantial amounts of both detyrosinated α-tubulin and acetylated α-tubulin. Our results indicate that such findings cannot be generalized across all species. L. stagnalis, with its well studied nervous system and unusual distribution of tubulin isoforms, may prove to be particularly useful for studying the roles of tubulin isoforms in microtubule function and cell activity.
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    GABA and glutamate-like immunoreactivity at synapses received by dorsal unpaired median neurones in the abdominal nerve cord of the locust (1995)
    Springer
    Cell & tissue research 280 (1995), S. 325-333 
    Details
    ISSN: 1432-0878
    Keywords: Key words: Nervous system ; insect ; DUM neuron ; Synapses ; Immunocytochemistry ; GABA ; Glutamate ; Locusta migratoria (Insecta) ; Schistocerca gregaria (Insecta)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. Dorsal unpaired median (DUM) neurones in the abdominal ganglia of the locust were impaled with microelectrodes and some were injected intracellularly with horseradish peroxidase so that their synapses could be identified in the electron microscope. Simultaneous recordings from DUM neurones in different abdominal ganglia revealed that they received common postsynaptic potentials from descending interneurones. Post-embedding immunocytochemistry using antibodies against GABA and glutamate was carried out on ganglia containing HRP-stained neurones. GABA-like immunoreactivity was found in 39% (n=82) of processes presynaptic to abdominal DUM neurones and glutamate-like immunoreactivity in 21% (n=42) of presynaptic processes. Output synapses from the DUM neurites were rarely observed within the neuropile. Structures resembling presynaptic dense bars but not associated with synaptic vesicles, were seen in some large diameter neurites.
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    Leu-callatostatin gene expression in the blowflies Calliphora vomitoria and Lucilia cuprina studied by in situ hybridisation: comparison with Leu-callatostatin confocal laser scanning immunocytochemistry (1995)
    Springer
    Cell & tissue research 280 (1995), S. 355-364 
    Details
    ISSN: 1432-0878
    Keywords: Key words: Leu-callatostatin ; Allatostatins ; Neuropeptides ; In situ hybridisation ; Immunocytochemistry ; Hindgut innervation ; Midgut endocrine cells ; Calliphora vomitoria ; Lucilia cuprina (Insecta)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. In situ hybridisation studies using a digoxigenin-labelled DNA probe encoding the Leu-callatostatin prohormone of the blowflies Calliphora vomitoria and Lucilia cuprina have revealed a variety of neurones in the brain and thoracico-abdominal ganglion, peripheral neurosecretory neurones, and endocrine cells of the midgut. With two exceptions, the hybridising cells are the same as those previously identified in immunocytochemical studies of sections and whole-mounts using Leu-callatostatin COOH-terminal-specific antisera. Within the brain and suboesophageal ganglion, there is a variety of neurones ranging from a single pair of large cells situated in the dorsal protocerebrum, to the several pairs of neurones in the tritocerebrum, some of which, in immunocytochemical preparations, can be seen to project via axons in the cervical connective to the thoracico-abdominal ganglion. In the medulla of the optic lobes, numerous small interneurones hybridise with the probe, as do clusters of similar-sized neurones close to the roots of the ocellar nerves. These results indicate that the Leu-callatostatin neuropeptides of the brain play a variety of roles in neurotransmission and neuromodulation. There are only three pairs of Leu-callatostatin-immunoreactive neurones in the thoracico-abdominal ganglion, at least two pairs of which project axons along the median abdominal nerve to provide extensive innervation of the hindgut. The Leu-callatostatin peripheral neurosecretory cells are located in close association with both nerve and muscle fibres in the thorax. In addition to neuronal Leu-callatostatin, the presence of the peptide and its mRNA has been demonstrated in endocrine cells in the posterior part of the midgut. These observations provide an example of a named brain/gut peptide in an insect.
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    Immunocytochemical localization of ribonuclease in yolk granules of adult Rana catesbeiana oocytes (1995)
    Springer
    Cell & tissue research 280 (1995), S. 259-265 
    Details
    ISSN: 1432-0878
    Keywords: Key words: Oocyte ; Yolk granules ; Ribonuclease ; Immunocytochemistry ; Bullfrog ; Rana catesbeiana (Anura)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. To determine the localization of the pyrimidine-guanine sequence-specific ribonuclease in Rana catesbeiana (bullfrog) oocytes, the RNase was first isolated and used to prepare a specific rabbit antiserum. Only one protein of similar molecular size to the RNase was immunoprecipitated from ovary homogenate by the antiserum, but two bands were observed by Western blotting analysis. These two proteins were shown by further purification of antibody and Western blotting analysis to have similar antigenicity. Immunoprecipitation and Western blotting of tissue homogenates showed that the RNase was found predominantly in the ovary, but not in other tissues. The specific localization of the RNase was determined by immuno-electron microscopy of oocyte sections incubated with the specific antiserum; the yolk granules, but not other organelles, were found to contain the RNase. Most of the RNase was evenly distributed in the lateral amorphous area of the yolk granule but not in the central yolk crystal area which contains stored vitellogenin proteins. Our results indicate that the RNase is compartmentalized in the yolk granules of oocytes, which might prevent damage to cellular RNAs.
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    Sources of inputs to longitudinal muscle motor neurons and ascending interneurons in the guinea-pig small intestine (1995)
    Springer
    Cell & tissue research 280 (1995), S. 549-560 
    Details
    ISSN: 1432-0878
    Keywords: Key words: Enteric nervous system ; Immunocytochemistry ; Calretinin ; Calbindin ; Bombesin ; Small intestine ; Guinea-pig
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. Light- and electron-microscopic studies were used to investigate connections between specific subgroups of neurons in the myenteric plexus of the guinea-pig small intestine. Inputs to two classes of calretinin-immunoreactive (IR) nerve cells, longitudinal muscle motor neurons and ascending interneurons, were examined. Inputs from calbindin-IR primary sensory neurons and from three classes of descending interneurons were studied. Electron-microscopic analysis showed that calbindin-IR axons formed two types of inputs, synapses and close contacts, on calretinin-IR neurons. About 40% of inputs to the longitudinal muscle motor neurons and 70% to ascending interneurons were calbindin-IR. Approximately 50% of longitudinal muscle motor neurons were surrounded by bombesin-IR dense pericellular baskets and 40% by closely apposed varicosities. At the electron-microscope level, the bombesin-IR varicosities were found to form synapses and close contacts with the motor neurons. Dense pericellular baskets with bombesin-IR surrounded 36% of all ascending interneurons, and a further 17% had closely apposed varicosities. Somatostatin- and 5-HT-IR descending interneurons provided no dense pericellular baskets to calretinin-IR nerve cells. Thus, calretinin-IR, longitudinal muscle motor neurons and ascending interneurons receive direct synaptic inputs from intrinsic primary sensory neurons and from non-cholinergic, bombesin-IR, descending interneurons.
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    Ultrastructural investigation of nitric oxide synthase-immunoreactive nerves associated with coronary blood vessels of rat and guinea-pig (1995)
    Springer
    Cell & tissue research 280 (1995), S. 575-582 
    Details
    ISSN: 1432-0878
    Keywords: Key words: Nitric oxide synthase ; Coronary vasculature ; Electron microscopy ; Immunocytochemistry ; Rat (Sprague Dawley) ; Guinea-pig (Dunkin Hartley)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. Ultrastructural investigation of nitric oxide synthase-immunoreactive nerves closely associated with blood vessels in rat and guinea-pig hearts revealed many labelled nerve fibres in the walls of the main branches of the coronary arteries, and in arterioles, capillaries and post-capillary venules. The number of nitric oxide synthase-containing nerve fibres associated with different vessels, even those of the same calibre, varied. Terminal regions of nitric oxide synthase-immunoreactive fibres were observed in the endocardium and myocardium. Nitric oxide synthase-labelled fibres displayed electron-dense immunoproduct in both varicose and intervaricose regions. Immunoreactive axonal varicosities contained both small and large synaptic vesicles. The characteristics of the nitric oxide synthase-immunoreactive nerve fibres observed in the heart and the possibility that these fibres represent the processes of intracardiac neurones and/or sensory neurones of extrinsic origin are discussed.
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    The distribution of neurones immunoreactive for β-tyrosine hydroxylase, dopamine and serotonin in the ventral nerve cord of the cricket, Gryllus bimaculatus (1995)
    Springer
    Cell & tissue research 280 (1995), S. 583-604 
    Details
    ISSN: 1432-0878
    Keywords: Key words: Dopamine ; Serotonin ; Tyrosine hydroxylase ; Immunocytochemistry ; Nervous system ; insect ; Gryllus bimaculatus (Insecta)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. The cellular localization of the biogenic amines dopamine and serotonin was investigated in the ventral nerve cord of the cricket, Gryllus bimaculatus, using antisera raised against dopamine, β-tyrosine hydroxylase and serotonin. Dopamine- (n≤70) and serotonin-immunoreactive (n≤120) neurones showed a segmental arrangement in the ventral nerve cord. Some neuromeres, however, did not contain dopamine-immunoreactive cell bodies. The small number of stained cells allowed complete identification of brain and thoracic cells, including intersegmentally projecting axons and terminal arborizations. Dopamine-like immunostaining was found primarily in plurisegmental interneurones with axons descending to the soma-ipsilateral hemispheres of the thoracic and abdominal ganglia. In contrast, serotonin-immunostaining occurred predominantly in interneurones projecting via soma-contralaterally ascending axons to the thorax and brain. In addition, serotonin-immunoreactivity was also present in efferent cells and afferent elements. Serotonin-immunoreactive, but no dopamine-immunoreactive, varicose fibres were observed on the surface of some peripheral nerves. Varicose endings of both dopamine- and serotonin-immunoreactive neurones occurred in each neuromere and showed overlapping neuropilar projections in dorsal and medial regions of the thoracic ganglia. Ventral associative neuropiles lacked dopamine-like immunostaining but were innervated by serotonin-immunoreactive elements. A colocalization of the two amines was not observed. The topographic representation of neurone types immunoreactive for serotonin and dopamine is discussed with respect to possible modulatory functions of these biogenic amines in the central nervous system of the cricket.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00318362
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  • 95
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    Putative neurohemal areas in the peripheral nervous system of an insect, Gryllus bimaculatus, revealed by immunocytochemistry (1995)
    Springer
    Cell & tissue research 281 (1995), S. 43-61 
    Details
    ISSN: 1432-0878
    Keywords: Key words: Neurohemal areas ; Neuropeptides ; Monoamines ; Immunocytochemistry ; Nervous system ; insect ; Gryllus bimaculatus (Insecta)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. The morphology and position of putative neurohemal areas in the peripheral nervous system (ventral nerve cord and retrocerebral complex) of the cricket Gryllus bimaculatus are described. By using antisera to the amines dopamine, histamine, octopamine, and serotonin, and the neuropeptides crustacean cardioactive peptide, FMRFamide, leucokinin 1, and proctolin, an extensive system of varicose fibers has been detected throughout the nerves of all neuromeres, except for nerve 2 of the prothoracic ganglion. Immunoreactive varicose fibers occur mainly in a superficial position at the neurilemma, indicating neurosecretory storage and release of neuroactive compounds. The varicose fibers are projections from central or peripheral neurons that may extend over more than one segment. The peripheral fiber varicosities show segment-specific arrangements for each of the substances investigated. Immunoreactivity to histamine and octopamine is mainly found in the nerves of abdominal segments, whereas serotonin im-munoreactivity is concentrated in subesophageal and terminal ganglion nerves. Immunoreactivity to FMRFamide and crustacean cardioactive peptide is widespread throughout all segments. Structures immunoreactive to leucokinin 1 are present in abdominal nerves, and proctolin immunostaining is found in the terminal ganglion and thoracic nerves. Codistribution of peripheral varicose fiber plexuses is regularly seen for amines and peptides, whereas the colocalization of substances in neurons has not been detected for any of the neuroactive compounds investigated. The varicose fiber system is regarded as complementary to the classical neurohemal organs.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00307957
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  • 96
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    Immunolocalization of the Na,K-ATPase in photoreceptor cells of the moth Manduca sexta– evidence for Na,K-ATPase on both the nonmicrovillar and the microvillar domains of the plasma membrane (1995)
    Springer
    Cell & tissue research 281 (1995), S. 119-126 
    Details
    ISSN: 1432-0878
    Keywords: Key words: Compound eye ; Photoreceptor cells ; Ion pumps ; Polarity ; Immunocytochemistry ; Manduca sexta (Insecta)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. Immunohistochemical and physiological studies on various insect photoreceptors have demonstrated that the Na,K-ATPase (sodium pump) is restricted to the nonreceptive nonmicrovillar area of the plasma membrane. Here, we examined the distribution of the Na,K-ATPase in photoreceptor cells of the superposition-type compound eye in the moth Manduca sexta. Using immunofluorescent and immunogold cytochemistry, we show that the Na,K-ATPase is localized to both the nonmicrovillar and the microvillar parts of the plasma membrane. Manduca photoreceptors thus deviate from the common concept that the sodium pump and the molecular components of the photoreceptive machinery reside on different domains of the plasma membrane.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00307965
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  • 97
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    Immunocytochemical colocalization of adhesive proteins with clathrin in human blood platelets: further evidence for coated vesicle-mediated transport of von Willebrand factor, fibrinogen and fibronectin (1995)
    Springer
    Cell & tissue research 279 (1995), S. 453-457 
    Details
    ISSN: 1432-0878
    Keywords: Key words: Blood platelets ; Immunocytochemistry ; Electron microscopy ; Coated vesicles ; Clathrin ; Adhesive proteins ; Human
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. Coated membranes and vesicles play an important role in receptor-mediated endocytosis and intracellular trafficking in various cell types, and are also present in blood platelets. Platelets take up certain proteins from the blood plasma, such as von Willebrand factor and fibrinogen, and these substances are transferred to storage granules. The receptors for these plasma proteins on the platelet plasma membrane have been well characterized, but morphological evidence for their transport to the storage granules is not yet available. In an attempt to clarify this aspect, we employed postembedding immunocytochemistry on platelets embedded in the acrylic resin LR White. Clathrin as the major coat component of coated vesicles was localized in the cytoplasm, on the plasmic faces of α-granules and the open canalicular system, and on the plasmic face of the plasma membrane. Colocalizations of the adhesive proteins, von Willebrand factor, fibrinogen and fibronectin, with clathrin could be observed at the same typical locations as coated vesicles were seen in Araldite-embedded material. These colocalizations have not been reported to date and furnish further evidence for a coated vesicle-mediated transport of blood plasma-derived adhesive proteins from their receptors on the outer plasma membrane to the α-granules.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410050304
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  • 98
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    Immunocytochemical colocalization of adhesive proteins with clathrin in human blood platelets: further evidence for coated vesicle-mediated transport of von Willebrand factor, fibrinogen and fibronectin (1995)
    Springer
    Cell & tissue research 279 (1995), S. 453-457 
    Details
    ISSN: 1432-0878
    Keywords: Blood platelets ; Immunocytochemistry ; Electron microscopy ; Coated vesicles ; Clathrin ; Adhesive proteins ; Human
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Coated membranes and vesicles play an important role in receptor-mediated endocytosis and intracellular trafficking in various cell types, and are also present in blood platelets. Platelets take up certain proteins from the blood plasma, such as von Willebrand factor and fibrinogen, and these substances are transferred to storage granules. The receptors for these plasma proteins on the platelet plasma membrane have been well characterized, but morphological evidence for their transport to the storage granules is not yet available. In an attempt to clarify this aspect, we employed postembedding immunocytochemistry on platelets embedded in the acrylic resin LR White. Clathrin as the major coat component of coated vesicles was localized in the cytoplasm, on the plasmic faces of α-granules and the open canalicular system, and on the plasmic face of the plasma membrane. Colocalizations of the adhesive proteins, von Willebrand factor, fibrinogen and fibronectin, with clathrin could be observed at the same typical locations as coated vesicles were seen in Araldite-embedded material. These colocalizations have not been reported to date and furnish further evidence for a coated vesicle-mediated transport of blood plasma-derived adhesive proteins from their receptors on the outer plasma membrane to the α-granules.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00318157
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  • 99
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    Localization of choline acetyltransferase-expresing neurons in the larval vissual system of Drosophila melanogaster (1995)
    Springer
    Cell & tissue research 282 (1995), S. 193-202 
    Details
    ISSN: 1432-0878
    Keywords: Choline acetyltransferase ; Cholinergic neuron ; Visual system ; Bolwig's organ ; Immunocytochemistry ; In situ hybridization ; Drosophila melanogaster (Insecta)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Choline acetyltransferease (ChAT) is the enzyme catalyzing the biosynthesis of acetylcholine and is considered to be a phenotypically specific marker for cholinergic neurons. We have examined the distribution of ChAT-expressing neurons in the larval nervous system of Drosophila melanogaster by three different but complementary techniques: in situ hybridization with a cRNA probe to ChAT messenger RNA, immunocytochemistry using a monoclonal anti-ChAT antibody, and X-gal staining of transformed animals carrying a reporter gene composed of 7.4 kb of 5′ flanking DNA from the ChAT gene fused to a lacZ reporter gene. All three techniques demonstrated ChAT-expressing neurons in the larval visual system. In embryos, the photoreceptor organ (Bolwig's organ) exhibited strong cRNA hybridization signals. The optic lobe of late third-instar larvae displayed ChAT immunoreactivity in Bolwig's nerve and a neuron close to the insertion site of the optic stalk. This neuron's axon ran in parallel with Bolwig's nerve to the larval optic neuropil. This neuron is likely to be a first-order interneuron of the larval visual system. Expression of the lacZ reporter gene was also detected in Bolwig's organ and the neuron stained by anti-ChAT antibody. Our observations indicate that acetylcholine may be a neurotransmitter in the larval photoreceptor cells as well as in a first-order interneuron in the larval visual system of Drosophila melanogaster.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00319111
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  • 100
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    Immunocytochemical localization of a vacuolar-type ATPase in Malpighian tubules of the ant Formica polyctena (1995)
    Springer
    Cell & tissue research 282 (1995), S. 343-350 
    Details
    ISSN: 1432-0878
    Keywords: Vacuolar ATPase ; Proton pump ; Electrogenic potassium transport ; Marpighian tubules ; Immunocytochemistry ; Formica polyctena (Insecta)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The presence of a vacuolar-type ATPase in Malpighian tubules of the ant Formica polyctena was investigated immunocytochemically, using antibodies to vacuolar ATPases of Manduca sexta midgut and bovine kidney. Specific labelling was observed at the brush border of the epithelium extending along the entire length of the tubules. These findings agree with the current view that a vacuolar ATPase is situated at the apical membrane of Malpighian tubule cells and other insect epithelial cells, being the energizing element of an electrogenic potassium pump. When antibodies were tested on tubules in different secretion conditions prior to fixation, no differences were observed in the distribution of the vacuolar ATPase.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00319124
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