ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Immunocytochemistry  (75)
  • Auxin
  • Chromatographie, Dünnschicht
  • Springer  (177)
  • 1995-1999  (31)
  • 1980-1984  (43)
  • 1975-1979  (103)
  • 1925-1929
  • 1998  (31)
  • 1980  (43)
  • 1978  (55)
  • 1977  (48)
Collection
Keywords
Publisher
  • Springer  (177)
Years
  • 1995-1999  (31)
  • 1980-1984  (43)
  • 1975-1979  (103)
  • 1925-1929
Year
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Calcified tissue international 24 (1977), S. 223-229 
    ISSN: 1432-0827
    Keywords: Enamel-cementum-morphology ; Immunocytochemistry ; Biochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The continuously erupting rabbit incisor tooth is normally thought of as having an enamel covered “crown” on its labial surface and a cementum covered “root” on its lingual surface. We have examined both surfaces of continuously erupting rabbit incisor teeth taken from near term embryos by a variety of means, including transmission and scanning electron microscopy, biochemical fractionation, and immunohistochemistry. In all cases, we could detect no qualitative difference in the early extracellular matrices taken from the labial and lingual surfaces of the teeth. Both matrices were shown to be composed of dentin and enamel, although the thickness and geometry of the enamel matrix on the lingual surface was somewhat different from that on the labial surface.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Planta 148 (1980), S. 510-512 
    ISSN: 1432-2048
    Keywords: Auxin ; Cell wall pH ; Growth (roots) ; Proton flux and growth ; Root growth ; Zea
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract At concentrations inhibitory to the elongation of corn (Zea mays L.) roots, the auxins, indole-3-acetic acid (IAA) and α-naphthaleneacetic acid (α-NAA), cause an increase in the pH of the bathing medium; this increase occurs with an average latent period shorter than the latent period for the inhibitory effect of these auxins on elongation. Indole-2-carboxylic acid, an inactive structural analogue of IAA, and β-naphthaleneacetic acid, an inactive analogue of α-NAA, affect neither growth nor the pH of the medium. Since acid pH is known to promote and basic pH to inhibit root elongation, the data are consistent with the hypothesis that hormone-induced modification of cell-wall pH plays a role in the control of elongation of roots, as has been proposed for elongation of stems and coleoptiles.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 1432-2048
    Keywords: Abscisic Acid ; Auxin ; Coleoptile ; Geotropism ; Root tip
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Isolated Avena coleoptiles were decapitated at different distances from the tip and then placed horizontally, after which the geotropic curvature was measured. No geotropic curvature could be detected during the first 3 h. Later, upward curvature occurred which was found to depend inversely on the length of the decapitated tips. When the tips of maize roots or Avena coleoptiles were placed on the cut surface of decapitated Avena coleoptiles, the coleoptiles showed a significantly stronger upward curvature as compared to controls which had been provided with agar blocks on the cut surface. The same upward curvature was found with decapitated coleoptiles provided with agar blocks containing 10-6 or 10-7 M indoleacetic acid (IAA). After application of abscisic acid (ABA) at concentrations of 10-6 and 10-8 M to the decapitated coleoptiles, the curvature observed was not different from that of the controls; at higher concentrations of ABA the curvature was found to be lower than that of the controls. It is concluded that root tips secrete a substance which may replace the effect of IAA in coleoptiles. The results are discussed in view of the validity of the Cholodny-Went hypothesis for the geotropic reaction of roots.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Planta 150 (1980), S. 255-263 
    ISSN: 1432-2048
    Keywords: Auxin ; Callus culture ; Phloem differentiation ; Sucrose ; Xylem differentiation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The differentiation of sieve and tracheary elements was studied in callus culture of Daucus carota L., Syringa vulgaris L., Glycine max (L.) Merr., Helianthus annuus L., Hibiscus cannabinus L. and Pisum sativum L. By the lacmoid clearing technique it was found that development of the phloem commenced before that of the xylem. In not one of the calluses was differentiation of tracheary elements observed in the absence of sieve elements. The influence of indole-3-acetic acid (IAA) and sucrose was evaluated quantitatively in callus of Syringa, Daucus and Glycine. Low IAA levels resulted in the differentiation of sieve elements with no tracheary cells. High levels resulted in that of both phloem and xylem. IAA thus controlled the number of sieve and tracheary elements, increase in auxin concentration boosting the number of both cell types. Changes in sucrose concentration, while the IAA concentration was kept constant, did not have a specific effect on either sieve element differentiation, or on the ratio between phloem and xylem. Sucrose did, however, affect the quantity of callose deposited on the sieve plates, because increase in the sucrose concentration resulted in an increase in the amount of callose. It is proposed that phloem is formed in response to auxin, while xylem is formed in response to auxin together with some added factor which reaches it from the phloem.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Planta 204 (1998), S. 515-519 
    ISSN: 1432-2048
    Keywords: Key words: Acid-growth theory (roots) ; Auxin ; Cell wall extensibility ; Rheology ; Root growth
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract. The rheological properties of corn (Zea mays L. cv. Garant) root elongation zones were investigated by means of a computer-controlled extensiometer. Creep closely followed a logarithmic time function, which was used to quantify creep activity. Pretreatment with auxin, which inhibits extension growth in roots, lowered the creep activity and the apparent plastic extensibility. While the time course of the inhibition of apparent plastic extensibility lagged behind the cessation of elongation growth, the drop in creep activity matched the growth inhibition more closely. Creep activity and apparent plastic extensibility were not significantly affected by pH. These data support the view that the auxin-induced cell wall stiffening (e.g. by cross-linking processes), while causal for the growth inhibition, is not brought about by a cell wall alkalinization.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    ISSN: 1432-2048
    Keywords: Key words: Auxin-induced genes ; Auxin ; Betaine ; Ectomycorrhiza ; Hypaphorine ; Root formation ; Root hair
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract. A full-length cDNA coding for a symbiosis-regulated transcript, EgHypar, was isolated by differential screening from a Eucalyptus globulus bicostata–Pisolithus tinctorius ectomycorrhiza. The sequence of this clone revealed a protein with an estimated molecular mass of 25.5 kDa that exhibited a high degree of homology (66%) with plant auxin-induced glutathione-S-transferases. Expression of the EgHypar gene in seedlings was confined largely in roots and it is drastically increased by ectomycorrhiza development. The concentration of EgHypar transcripts was similarly up-regulated in roots incubated in media supplemented with P. tinctorius cell-free extracts, indole-3-acetic acid, 2,4-dichlorophenoxyacetic acid or hypaphorine (tryptophan betaine), the major indolic compound secreted by P. tinctorius. The latter fungal alkaloid concomitantly induced a decrease in root hair elongation in eucalypt seedlings. Up-regulation of EgHypar expression by auxins and fungal metabolites suggests that this symbiosis-regulated gene could be involved in the morphological changes taking place in plants roots upon symbiosis development. To our knowledge, these results provide the first molecular evidence that gene expression of the host plant is altered by molecules produced by the ectomycorrhizal mycobiont.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Planta 134 (1977), S. 145-149 
    ISSN: 1432-2048
    Keywords: Affinity labels ; Auxin ; Cell membranes ; Hormone Receptors ; Receptors ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Two auxin analogues have been tested as affinity labels for auxin binding sites in coleoptile membranes of Zea mays L. Reacting the membranes at pH 8–9 with the diazonium salt of CAPA (2-chloro-4-aminophenoxyacetic acid) reduces their subsequent ability to bind NAA(1-naphthylacetic acid). Diazo-Chloramben (2,5-dichloro-3-aminobenzoic acid) is also effective in inhibiting NAA binding capacity and this inhibition is largely independent of reaction pH over the range pH 6–9. Similar experiments with sulphydryl reagents have shown that reaction of the membranes with p-mercuribenzoate (PMB) strongly inhibits subsequent auxin binding activity. Prior addition of NAA protects the binding sites against the action of diazo-Chloramben or PMB when the reactions are carried out at pH 6. From these results and from other considerations, several of the amino acid residues in the binding site environment have been tentatively assigned.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    ISSN: 1432-2048
    Keywords: Auxin ; Avena ; Helianthus ; pH drop ; Pisum ; Protoplast suspension
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Several indoleacetic acids, substituted in the benzene ring, were compared in the Avena straight growth bioassay. 4-Chloroindoleacetic acid, a naturally occurring plant hormone, is one of the strongest hormones in this bioassay. With an optimum at 10-6 mol l-1, it is more active than indoleacetic acid, 2,4-dichlorphenoxyacetic acid and naphthaleneacetic acid. 5-Chloro- and 6-chloroindoleacetic acids are very strong auxins as well. Other derivatives tested have a lower activity. 5,7-Dichloro- and 5-hydroxyindoleacetic acids have very low auxin activity at 10-4 mol l-1 and may be anti-auxins. Some of the derivatives were compared for their effect on pH decline in stem protoplast suspensions of Helianthus annuus L. and Pisum sativum L. The change of pH occurs without a lag period or with only a very short one. Derivatives which are very active in the Avena straight growth assay cause a larger pH decline than indoleacetic acid, while inactive derivatives cause effectively no pH decline.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Planta 140 (1978), S. 107-109 
    ISSN: 1432-2048
    Keywords: Auxin ; Leaf movement ; Phaseolus ; Pulvinus ; Turgor movement
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Auxin application to the upper side of the pulvinus of primary leaves of Phaseolus vulgaris L. promoted bending away from the place of application. The effect had a latency of less than 20 min and was specifically induced by substances known as active auxins in growth tests (indoleacetic and 1-naphthaleneacetic acid) but not by inactive auxin analogs (2-naphthaleneacetic, 3-indolepropionic and benzoic acid); 2,4-dichlorophenoxyacetic acid, and L-(-)-2,4-dichlorophenoxyisopropionic acid were of intermediate activity. Auxin-promoted bending was reversible and presumably caused by turgor increase in the treated cells.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Planta 140 (1978), S. 201-211 
    ISSN: 1432-2048
    Keywords: Auxin ; Cell elongation ; Coleoptiles ; Fusicoccin ; Zea
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract To analyze early effects of auxin application, an apparatus was developed which continuously and simultaneously registered the curvature of 10 individual maize (Zea mays L.) coleoptiles. Resolution was less than 5 μm over a range of ±0.5 mm. The data were evaluated and plotted via paper tape and Hewlett-Packard-computer. Unilateral application of 3×10-5 M indoleacetic acid (IAA) resulted in a transient inhibition of growth on the side of application for ca. 10 min (Phase I), followed by a strong stimulation (Phase II). The phytotoxin fusicoccin (FC) caused an immediate stimulation of elongation. The initial negative reaction of Phase I is auxin-specific. Only active auxins such as IAA and 1-naphtaleneacetic acid produced this initial inhibition; chemical analogs-inhibitory or neutral in long-term growth tests, e.g. phenylacetic acid-did not show any significant effects on Phase I. When the coleoptiles were symmetrically preloaded with different levels of auxin, only a large step-up of subsequent unilateral auxin application resulted in a negative phase I; a small step-up led to an immediate positive reaction. The results are discussed in context with the parallel kinetics for various other auxin-induced reactions of coleoptile cells which have already been published.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 11
    Electronic Resource
    Electronic Resource
    Springer
    Planta 136 (1977), S. 97-102 
    ISSN: 1432-2048
    Keywords: Acid growth ; Auxin ; Ethylene ; Fusicoccin ; Growth inhibition ; Lens ; Root growth
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Both acid pH (4.0) and fusicoccin (FC) strongly stimulate root elongation in intact lentil (Lens culinaris Med.) seedlings. FC-induced elongation is apparently mediated by FC-enhanced H+ secretion since the toxin induces massive secretion of H+ in these roots after a latent period of less than 5 min. Auxin (indole-3-acetic acid) strongly inhibits elongation in control roots as well as acid-induced and FC-induced root elongation. Treatment of apical root segments with auxin causes only a slight apparent uptake of H+ and has no inhibitory effect on FC-induced H+ secretion, whether the hormone is given before or after the toxin. Auxin induces ethylene production in excised roots of lentil but the latent period is at least 30 min while inhibition of root elongation by IAA is maximal within 30 min. It is concluded that the inhibitory action of auxin on acid-and fusicoccin-induced root elongation is a direct effect, independent of auxin-induced ethylene production or auxin-mediated modification of cell-wall pH.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 12
    ISSN: 1432-2048
    Keywords: Abelmoschus ; Auxin ; Gibberellin ; Root formation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Indole-3-acetic acid (IAA) and gibberellic acid (GA3) enhanced the formation of roots on the stem cuttings of Abelmoschus esculentus. The effect increased considerably when both IAA and GA3 were applied together.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 13
    Electronic Resource
    Electronic Resource
    Springer
    Planta 138 (1978), S. 107-110 
    ISSN: 1432-2048
    Keywords: Auxin ; Nitrogen fixation (asymbiotic) ; Pisum ; Rhizobium
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Treatment of epicotyls of dark-grown pea (Pisum sativum L.) seedlings with indole-3-acetic acid causes swelling of the tissue. Application of Rhizobium to the cut surface of the swollen tissue results in the development of an “infection”. The infection spreads in the cortical cells and proceeds 2–3 mm deep into the stem within 3–4 days. An acetylene reduction assay used for detecting nitrogen-fixation capacity of the infected tissue was negative at 10% [O2]; however, if [O2] was reduced to below 1%, some activity could be detected. Ultrastructural observations indicate that the cytoplasmic contents of the infected cells are destroyed and no membrane structure around the bacteria is formed during this infection. Rhizobium does not appear to have developed any symbiotic relationship with the host. Failure to develop symbiosis appears to result in a parasitic or saprophytic association and the nitrogen fixed under such conditions may not be of any use to the plant.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 14
    Electronic Resource
    Electronic Resource
    Springer
    Planta 138 (1978), S. 181-184 
    ISSN: 1432-2048
    Keywords: Abscisic acid ; Auxin ; Cannabis ; Cytokinin ; Flowers (sex) ; Gibberellin ; Sex expression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Application, through the root system, of growth regulators to hemp (Cannabis sativa L.) plants having 2–3 pairs of visible leaves caused pronounced shifts of sex expression in the adult individuals. Treatment with gibberellic acid (25 mg/l) resulted in more than 80% of the plants being male, i.e. having staminate flowers (controls, ca. 30%). Treatment with 6-benzylaminopurine and with indole-3-acetic acid (in either case, 15 mg/l) resulted in all plants being either female (pistillate flowers) or intersexes (bisexual flowers); treatment with abscisic acid (10 mg/l) had a similar but somewhat less pronounced effect.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 15
    ISSN: 1432-2048
    Keywords: Auxin ; Ethylene ; Root formation ; Vigna
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Rooting responses and ethylene production by hypocotyl cuttings from etiolated mung-bean seedlings treated with the auxins α-naphthaleneacetic acid, γ-(indole-3)-n-butyric acid (IBA) and 2,4,5-trichloro-phenoxypropionic acid were determined. There was no relationship between the abilities of the auxins to induce root formation and their capacities for inducing ethylene production. Studies with mixtures of 3-indoleacetic acid, a poor stimulator of rooting but an effective inducer of ethylene production, and IBA, an effective rooting stimulator but a poor inducer of ethylene production, exposure of cuttings to ethylene or (2-chloroethyl) phosphonic acid (Ethephon), hypobaric storage (150 mb) of treated cuttings, and exposure of auxin-treated cuttings to 7% CO2 also indicated that ethylene is not directly involved in initiation of adventitious roots in this plant material.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 16
    ISSN: 1432-2048
    Keywords: Auxin ; Fusicoccin ; Glucose transport ; Proton flux ; Roots ; Zea
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Auxin and fusicoccin (FC) stimulate the active uptake of 3-O-methyl glucose (3-O-MG) in those materials in which they have been shown to activate an electrogenic proton extrusion (Pisum sativum L. stems, Zea mays L. coleoptiles and roots). In maize roots the curve relating 3-O-MG influx to external concentrations indicated that the values of the apparent Km increase in the 3-O-MG concentration range between 2×10-5 mol l-1 and 2×10-2 mol l-1. FC did not alter the Km values and its stimulating effect was nearly constant at all 3-O-MG concentrations tested. Basal and FC-induced uptake of 3-O-MG appeared associated with a transient proton influx suggesting that also in maize roots a sugar-proton contransport occurs. Diethyl stilbestrol, which inhibits proton extrusion, inhibited also basal and FC-induced 3-O-MG uptake. The data support the view that the stimulation by FC of 3-O-MG uptake is closely related to that of proton extrusion. The stimulation by FC of 3-O-MG uptake cannot be replaced by increasing extracellular proton concentration, nor may be explained only by the FC-induced hyperpolarization of transmembrane potential difference. The hypothesis is proposed that the effect of FC on 3-O-MG uptake depends on an increase of cytoplasmic pH, following the activation of the proton extruding system.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 17
    ISSN: 1432-2048
    Keywords: Avena ; Immunocytochemistry ; Phytochrome
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Phytochrome of oat (Avena sativa L., cv. Garry) coleoptile cells in the red-light-absorbing form, Pr, is diffusely distributed while after conversion to the far-red-light-absorbing form, Pfr, it is observed only in very small areas within the cell. Comparison of phytochrome photoversibility measurements to the distribution of the pigment within the cell indicates that the spectral assay is not influenced by the observed compartmentalization of the chromoprotein. However, the observed compartmentalization of phytochrome is correlated with a loss in spectrophotometrically detectable Pr.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 18
    Electronic Resource
    Electronic Resource
    Springer
    Planta 141 (1978), S. 179-181 
    ISSN: 1432-2048
    Keywords: Auxin ; Maize ; Root tip ; Zea
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract [5-3H]Indol-3yl-acetic acid (IAA) applied to the shoot apices of intact 6-day-old maize (Zea mays L.) plants moved into the primary root and accumulated at the root apex. IAA from the shoot could partially satisfy the requirement of the primary root for IAA for growth.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 19
    ISSN: 1432-2048
    Keywords: AMO-1618 ; Antiauxin ; Auxin ; Bromodeoxyuridine ; Cell (fiber) growth ; Gibberellin ; Gossypium ; Ovules (in-vitro culture)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The effects of 5-bromo-2-deoxyuridine (BUdR, thymidine analogue), AMO-1618 (2-isopropyl-4-dimethylamino-5-methylphenyl-1-piperidine carboxylate methyl chloride), a growth retardant, and p-chlorophenoxyisobutyric acid (PCIB, an antiauxin) on growth (dry weight increase) and fiber development in unfertilized cotton (Gossypium hirsutum L.) ovules grown in vitro have been studied. BUdR (5 μM) causes about 70% inhibition of fiber production, with little effect on ovule growth, if applied during the first 6 d of culture in the presence of GA3 and IAA. AMO-1618, when used with GA3 alone, causes only a small reduction in both dry weight and fiber production, but when used with IAA alone reduces both fiber production and dry weight, the effect on the latter being predominant. In the presence of both IAA and GA3, AMO-1618 causes a small decrease in fiber production but a major decrease in dry weight. PCIB completely inhibits fiber growth but has little effect on dry weight, especially when GA3 is present. These results indicate that GA3 mainly promotes ovule growth while IAA is largerly responsible for fiber growth.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 20
    ISSN: 1432-2048
    Keywords: Auxin ; Chlorophyll content ; Chloroplast ; Photosynthetic rate ; Raphanus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Dark-grown radish seedlings (Raphanus sativus L.) were sprayed with 10-3 mol·l-1 2,4-dichlorophenoxyacetic acid and then were exposed to a 14:10 light: dark cycle. Cotyledon samples from these seedlings and unsprayed controls were taken for electron microscopy, chlorophyll determinations, and photosynthetic rate measurements at regular intervals for 72 h. A normal development of etioplasts to chloroplasts with formation of typical grana-fret work system was observed in the control cotyledons. The chloroplasts in the 2,4-D-treated cotyledons showed changes in the organization of the grana thylakoids; these thylakoids being more appressed to each other than in the controls. The chlorophyll content of treated plants was less than that of controls but the rate of chlorophyll biosynthesis was unaffected. The photosynthetic rate/mg chlorophyll was considerably higher for treated plants suggesting that 2,4-D treatment resulted in decreased size of the photosynthetic unit.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 21
    Electronic Resource
    Electronic Resource
    Springer
    Planta 144 (1978), S. 39-47 
    ISSN: 1432-2048
    Keywords: Aquatic plants ; Auxin ; Cell elongation ; Ethylene ; Ethylene biosynthesis ; Silverions
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Elongation of the shoots of three aquatic plants (Hydrocharis morsus-ranae, Regnellidium diphyllum and Ranunculus sceleratus) is stimulated by treatment with ethylene or IAA. The effects of the two hormones are additive, and experiments with an ethylene biosynthesis inhibitor and silver ions indicate that the mechanisms by which ethylene and IAA stimulate growth may be different. Hydrocharis and Ranunculus leaf discs synthesize [14C]ethylene from [14C]methionine, but no [14C]ethylene is formed by Regnellidium, suggesting the existence of an alternative pathway of ethylene biosynthesis in the fern.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 22
    Electronic Resource
    Electronic Resource
    Springer
    Planta 136 (1977), S. 173-180 
    ISSN: 1432-2048
    Keywords: Auxin ; Immunoassay ; Nicotiana ; Radioimmunoassay
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We have developed a specific radioimmunoassay [RIA] for indole-3-acetic acid (IAA) in the 0.2 ng to 12 ng range which, in principle, can be extended to other indole auxins as well. Methods are presented for obtaining suitable antibody, for the RIA procedure, and for measuring IAA in methanolic extracts of plant tissues. Antibody specific for IAA was obtained from rabbits immunized with IAA bound to bovine serum albumin by formaldehyde treatment. In assays with this antibody, 2,4-dichlorophenoxyacetic acid and indoles structurally related to IAA reacted from 300- to 3000-fold less than did IAA itself. However, α-and β-naphthaleneacetic acid reacted significantly and hence interfered with the assay. Extracts of tobacco (Nicotiana tabacum L.) tissue were immunoassayed after partial purification by buffer-ether partition. Crown-gall tumor tissue, which is auxin-autotrophic, and pith tissue depleted of auxin by the diffusion method contained, respectively, 26.7 ng and 〈0.5 ng extractable IAA per gram fresh weight.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 23
    ISSN: 1432-2048
    Keywords: Auxin ; Calcium ions ; Cell growth ; Gibberellin ; Membrane permeability ; Membrane potential ; Zea
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The membrane potential difference of dwarf maize coleoptile cells is increased by both 10-5moll-1 gibberellic acid (GA3) and indoleacetic acid (IAA) a few minutes after application. A final level is reached after 10–20 min. The membrane permeability ratio P Na:P K is altered by both hormones during the first 15 min after application, indicating a rapid effect on the membrane. Elongation growth of coleoptile segments, however, is only stimulated by IAA. The auxin-induced growth as well as the auxin effect on membrane permeability depends on the calcium ion concentration of the medium. It is concluded that IAA acts via a proton extrusion pump that is electrically balanced by a potassium ion uptake, driven by the electromotive force of the pump. The mode of action of GA3 on elongation growth is assumed to involve a process that depends on the physiologic state of the tissue and/or metabolic energy.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 24
    Electronic Resource
    Electronic Resource
    Springer
    Planta 140 (1978), S. 31-35 
    ISSN: 1432-2048
    Keywords: Auxin ; Coleoptiles ; Electrical Potential ; Zea
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Following asymmetric application of indoleacetic acid to maize (Zea mays L.) coleoptiles the early time course of changes in lateral electrical potential was externally monitored with static-drop electrodes. First, an early negative potential change of ca.-1 mV was measured at the surface on the side of a strong auxin application. This negative auxin effect ended after ca. 15 min and was followed by a strong and lasting auxin stimulation of a positive lateral potential up to +12 mV at the auxin-treated side. The initial auxin effect appeared to depend on the size of the step-up in auxin concentration.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 25
    Electronic Resource
    Electronic Resource
    Springer
    Planta 140 (1978), S. 137-142 
    ISSN: 1432-2048
    Keywords: Auxin ; Cell elongation ; Proton secretion ; Triticum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Growth of Triticum aestivum L. cv. Cappelle Desprez coleoptiles is promoted by 5.7×10−5 M indole acetic acid (IAA) as effectively in pH 3.4 buffer as in water, but IAA is not effective in the presence of buffer at pH 3.0 or 3.2 A combination of 5.7×10−5 M IAA and pH 3.4 buffer promotes growth to a greater extent than pH 3.2 buffer alone, which is optimal for acid-induced growth. IAA employed at 10−7 M is still effective at promoting growth in the presence of pH 3.4 buffer, moreover, IAA at 10−7 M interacts synergistically with the acidic buffer to promote growth. It is concluded that IAA and acid promote growth via separate mechanisms, and that IAA does not promote cell wall loosening by rendering the cell wall more acid.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 26
    ISSN: 1432-2048
    Keywords: Cotyledons ; Endoplasmic reticulum ; Ferritin labeling ; Immunocytochemistry ; Phaseolus ; Protein (reserve) ; Reserve protein
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The ultrastructure of the storage parenchyma cells of the cotyledons of developing bean (Phaseolus vulgaris L.) seeds was examined in ultrathin frozen sections of specimens fixed in a mixture of glutaraldehyde, formaldehyde and acrolein, infused with 1 M sucrose, and sectioned at-80° C. Ultrastructural preservation was excellent and the various subcellular organelles could readily be identified in sections which had been stained with uranyl acetate and embedded in Carbowax and methylcellulose. The cells contained large protein bodies, numerous long endoplasmic reticulum cisternae, mitochondria, dictyosomes, and electron-dense vesicles ranging in size from 0.2 to 1.0 μm. Indirect immunolabelling using rabbit immunoglobulin G against purified phaseolin (7S reserve protein), and ferritin-conjugated goat immunoglobulin G against rabbit immunoglobulin G was used to localize phaseolin. With a concentration of 0.1 mg/ml of anti-phaseolin immunoglobin G, heavy labeling with ferritin particles was observed ober the protein bodies, the cisternae of the endoplasmic reticulum, and the vesicles. The same structures were lightly labeled when the concentration of the primary antigen was 0.02 mg/ml. Ferritin particles were also found over the Golgi bodies. The absence of ferritin particles from other organelles such as mitochondria and from areas of cytoplasm devoid of organelles indicated the specificity of the staining, especially at the lower concentration of anti-phaseolin immunoglobulin G.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 27
    Electronic Resource
    Electronic Resource
    Springer
    Planta 144 (1978), S. 79-84 
    ISSN: 1432-2048
    Keywords: Auxin ; Cell elongation ; Lead ; Triticum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In vitro studies of IAA-induced cell elongation in Triticum aestivum have demonstrated that lead causes a large reduction in elongation. Inhibition of elongation can be reduced by increasing the concentration of IAA, or by the addition of calcium. The inhibitory effect appears to be linked with changes in the properties of the cell walls. Experiments are described which show that lead becomes bound strongly to certain chemical substances involved in cell wall architecture.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 28
    Electronic Resource
    Electronic Resource
    Springer
    Planta 147 (1980), S. 444-450 
    ISSN: 1432-2048
    Keywords: Abscisic acid ; Auxin ; Cytokinin ; Decapitation ; Fruit-set ; Gibberellin ; Parthenocarpy ; Pisum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The influence of removing the apical shoot and different leaves above and below the flower on the fruit-set of unpollinated pea ovaries (Pisum sativum L. cv. Alaska) has been studied. Unpollinated ovaries were induced to set and develop either by topping or by removing certain developing leaves of the shoot. Topping had a maximum effect when carried out before or on the day of anthesis, and up to four consecutive ovaries were induced to set in the same plant. The inhibition of fruit-set was due to the developing leaves and not to the apex. The third leaf above the first flower, which had a simultaneous development to the ovary, had the stronger inhibitory effect on parthenocarpic fruit-set. The application of different plant-growth regulators (indoleacetic acid, naphthylacetic acid, 2,4-dichlorophenoxyacetic acid, gibberellic acid, benzyladenine and abscisic acid) did not mimic the negative effect of the shoot.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 29
    Electronic Resource
    Electronic Resource
    Springer
    Planta 147 (1980), S. 451-456 
    ISSN: 1432-2048
    Keywords: Abscisic acid ; Auxin ; Fruit-set ; Gibberellin ; Parthenocarpy ; Pisum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The development of parthenocarpic fruits of Pisum sativum L. cv. Alaska was induced by the application of different plant-growth regulators in aqueous solution to the emasculated ovaries in untopped plants. At least one compound in each of the groups of auxins (2,4-dichlorophenoxyacetic acid), cytokinins (benzyladenine), and gibberellins (gibberellic acid) was found active. Gibberellic acid (GA3), however, was the only substance which produced pods similar to those of fruits with seeds. The length of the pods obtained by GA3 was a linear function of the logarithm of the concentration of GA3 in the solution. The effect of GA3 (at a concentration which produced 50% of the maximum pod length) was enhanced by a simultaneous application of 2,4-dichlorophenoxyacetic acid. Abscisic acid (ABA) counteracted the effect of GA3 and of topping. The results suggest that gibberellins and ABA may exert a major regulatory control in natural fruit-set. Peas can be used for the assay of fructigenic activity and is an advantageous material for the study of the mode of action of gibberellins on fruit-set.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 30
    ISSN: 1432-2048
    Keywords: Auxin ; Branch angle ; Conifers ; Cupressus ; Ethylene ; Gibberellin ; Hyponasty
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Decapitation, gibberellin A3, high light, their combination, and certain levels of indole-3-acetic acid increase ethylene evolution and also induce branch hyponasty (upturning) in seedlings of Cupressus arizonica Greene, the increase in ethylene preceding obvious hyponasty. Exogenous ethylene also causes branch hyponasty and branches of seedlings maintained in an atmosphere scavenged of ethylene by mercuric perchlorate grow downwards. It is concluded that ethylene may play a role in the apical control of branch angle in some conifers. The positive effect of ethylene in increasing branch hyponasty may be direct, or reflect changes in levels of endogenous auxin and/or gibberellin.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 31
    Electronic Resource
    Electronic Resource
    Springer
    Planta 148 (1980), S. 510-512 
    ISSN: 1432-2048
    Keywords: Auxin ; Cell wall pH ; Growth (roots) ; Proton flux and growth ; Root growth ; Zea
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract At concentrations inhibitory to the elongation of corn (Zea mays L.) roots, the auxins, indole-3-acetic acid (IAA) and α-naphthaleneacetic acid (α-NAA), cause an increase in the pH of the bathing medium; this increase occurs with an average latent period shorter than the latent period for the inhibitory effect of these auxins on elongation. Indole-2-carboxylic acid, an inactive structural analogue of IAA, and β-naphthaleneacetic acid, an inactive analogue of α-NAA, affect neither growth nor the pH of the medium. Since acid pH is known to promote and basic pH to inhibit root elongation, the data are consistent with the hypothesis that hormone-induced modification of cell-wall pH plays a role in the control of elongation of roots, as has been proposed for elongation of stems and coleoptiles.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 32
    Electronic Resource
    Electronic Resource
    Springer
    Planta 142 (1978), S. 207-210 
    ISSN: 1432-2048
    Keywords: Abscisic acid ; Auxin ; Cytokinin ; Flowers (sex) ; Gibberellin ; Sex expression ; Spinacia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract When 7-d-old plantlets of spinach (Spinacia oleracea L.) were immersed with their roots for 24 h in 25 mg/l gibberellic acid (GA3), or 15 mg/l 6-benzylaminopurine (6-BAP), or 15 mg/l indole-3-acetic acid (IAA), or 10 mg/l abscisic acid (ABA) and subsequently grown on long (18-h) days, the ratio of plants with male and female flowers, which in the controls was almost 1:1 (48 and 52%, respectively), was greatly altered. The treatments with 6-BAP, IAA and ABA raised the percentage of female plants to 88, 76 and 71%, respectively; the GA3 treatment increased the percent of male plants to 79%. When young, vegetative spinach plants (3 visible leaves) grown in 18-h days were cut a the root neck, and the shoots grown with their bases in nutrient solution, with adventitious roots either being allowed to develop or being systematically removed, 85% of the plants without roots became males, 85% of those with roots became females. But if the cut shoots were first, for 28 h, placed in a 15-mg/l 6-BAP solution and then grown in the absence of roots, the percent of female plants was restored to 84. These results fully agree with those obtained previously with hemp, namely, that plant growth regulators exert a regulating effect on the sex expression of dioecious plants when applied through the roots in early stages of development; that the root system plays an important role in determining the sex of these plants, that this role of the roots is associated with the synthesis of cytokinins in them. Dioecious short- and long-day plants do not differ in these respects.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 33
    ISSN: 1432-2048
    Keywords: Auxin ; Benzoxazolinones ; Receptors ; Supernatant factor ; Zea
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A naturally-occurring material termed ‘supernatant factor’ [Ray, P.R., Dohrmann, U., Hertel, R.: Plant Physiol. 59. 357–364 (1977)], which has the property of modifying the binding affinity of auxins to receptor sites, has been isolated from corn (Zea mays L.) and characterised as a mixture of 6-methoxy-2-benzoxazolinone (MBOA) and 6,7-dimethoxy-2-benzoxazolinone (DMBOA). DMBOA is about 50 times more active than MBOA in inhibiting binding of the auxin 1-naphthylacetic acid to membrane-bound or solubilised receptors. The activity of these compounds and the parent analogue in inhibiting auxin binding is correlated with their ability to inhibit auxin-induced growth.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 34
    ISSN: 1432-2048
    Keywords: Auxin ; Compartmental analysis ; Ion fluxes ; Petroselinum ; Suspension culture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Transport of 86Rb+/K+, 22Na+, 36Cl−, and [3H]indole acetic acid (IAA) has been studied on suspension-cultured cells of the parsley, Petroselinum crispum (Mill) Nym. By compartmental analysis two intracellular compartments of K+, Na+, and Cl− have been identified and ascribed to the cytoplasm and vacuole; half-times of exchange were around 200 s and 5 h, respectively. According to the Ussing-Teorell flux equation, active transport is required for the influx into the cytoplasm at the plasmalemma (K+, Cl−) and the tonoplast (K+, Na+, Cl−). The plasmalemma permeability pattern, PK:PNa:PCl=1.00:0.24:0.38, features an increased chloride permeability compared with cells from higher plant tissues. IAA uptake showed an exponential timecourse, was half-maximal after 10 min, and a linear function of the IAA concentration from 10−9 to 10−5 M. IAA and 2,4-dichlorophenoxy acetic acid reduce the apparent influx of K+, Na+, Cl− during the initial 30 min after addition and subsequently accelerate both in- and efflux of these ions. We discuss that auxins could affect the ion fluxes in a complex way, e.g. by protonophorous activity and by control of the hypothetical proton pump.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 35
    ISSN: 1432-2048
    Keywords: Abscisic Acid ; Auxin ; Geotropism ; Root tip ; Zea
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The effect of externally applied indoleacetic acid (IAA) and abscisic acid (ABA) on the growth of roots of Zea mays L. was measured. Donor blocks of agar with IAA or ABA were placed laterally on the roots and root curvature was measured. When IAA was applied to vertical roots, a curvature directed toward the donor block was observed. This curvature corresponded to a growth inhibition at the side of the root where the donor was applied. When IAA was applied to horizontal roots from the upper side, normal geotropic downward bending was delayed or totally inhibited. The extent of retardation and the inhibition of curvature were found to depend on the concentration of IAA in the donor block. ABA neither induced curvature in vertical roots nor inhibited geotropic curvature in horizontal roots; thus the growth of roots was not inhibited by ABA. However, when, instead of donor blocks, root tips or coleoptile tips were placed onto vertical roots, a curvature of the roots was observed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 36
    ISSN: 1432-2048
    Keywords: Abscisic acid ; Auxin ; Glucose-transport ; Glycine-transport ; Lemna ; Membrane potential ; Respiration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The membrane potential of Lemna gibba G1 was measured with a microelectrode; glucose and glycine uptake were measured with 14C-labeled substances. The membrane potential was increased by 85 mV on the average, after the plants had been pretreated with 10 μM abscisic acid (ABA) for more than 30 min. This effect is not linked to the endogenous level of soluble sugars. The concentration of these soluble sugars was increased to more than 200% by pretreatment of the plants with ABA, however, the respiration of the plants was not affected. ABA stimulated uptake of glucose and glycine. Glucose- and glycine-dependent depolarization and repolarization of the membrane was altered: depolarization was less and repolarization was slower; during uptake of glycine, the first typical phase of repolarization was suppressed. The data suggest that ABA interferes with the primary steps of substrate uptake.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 37
    ISSN: 1432-2048
    Keywords: Abscisic acid ; Auxin ; Cytokinin ; Ethylene ; Gibberellin ; Triticum ; Water stress
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Abscisic acid (ABA) inhibits the production of ethylene induced by water stress in excised wheat leaves and counteracts the stimulatory effect of 6-benzyladenine (BA) on this process. The stimulatory effect of BA and the inhibitory effect of ABA were equally pronounced whether external or endogenous ethylene levels were determined. When leaves were sprayed or floated on solutions of BA, indole-3-acetic acid (IAA), gibberellic acid (GA3), or ABA, the relative activities of these growth regulators on stress-induced ethylene at 10-4 mol l-1 were BA〉IAA 〉GA3〉controls〉ABA. In non-stressed leaves, however, where the levels of ethylene produced were 2–20 times smaller, the relative activities were IAA 〉BA〉GA3〉controls〉ABA. The effects of BA and ABA spray treatment on water stress induced ethylene were closely similar whether the solutions were applied 2 or 18 h prior to the initiation of water stress. The relationships between the levels of endogenous growth regulators in the plant and ethylene release induced by water stress are discussed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 38
    ISSN: 1432-2048
    Keywords: Auxin ; Cytokinin ; 5-Fluorouracil ; Helianthus ; Ribosome synthesis and activity ; Tuber
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In order to examine the relation of protein synthesis to the onset of growth, changes in ribosome content and activity were compared in aged, metabolically active Jerusalem artichoke (Helianthus tuberosus L.) slices incubated in water or 2,4-dichlorophenoxyacetic acid+kinetin. In water, cells do not grow or divide and rRNA and protein levels remain constant. The percentage membrane-bound (mb) ribosomes drops from 25% to 16% during 24h. At the same time the proportion of ribosomes active in protein synthesis in both free and mb populations declines from about 69% to 54%. In auxin+kinetin, cell expansion occurs and is accompanied by a 3-fold increase in rRNA and a 50% increase in total protein content. The percentage mb ribosomes remains at 25% throughout 48 h of growth. During the first 24h of growth 70% of ribosomes in both free and mb populations are active; this value declines to near water levels at 48 h. Considering the large increase in total ribosomes the number of synthetically active ribosomes is substantially increased during growth. 5-Fluorouracil (5-FU) does not inhibit hormone induced growth but does depress total rRNA content by about one-third. It also reduces [3H]uridine incorporation into ribosomes by 70% and the newly made ribosomes are mostly inactive in protein synthesis. On the other hand, the inhibitor does not significantly affect the proportion of total ribosomes active in protein synthesis and only partially reduces protein accumulation during the second 24 h of growth. It is suggested that while ribosome production is reduced in 5-FU, ribosome turnover is also retarded resulting in retention of near normal capacity for protein synthesis and growth.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 39
    Electronic Resource
    Electronic Resource
    Springer
    Planta 135 (1977), S. 289-295 
    ISSN: 1432-2048
    Keywords: Antiauxin ; Auxin ; Meristem differentiation ; Riella
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract During the development of the unistratose gemmae of Riella helicophylla, the single intercalary meristem of the very young gemmae is subdivided into two lateral meristems. The duration of the cell reproduction cycle increases from the margin to the median part of the gemmae. This polarization within the meristem disappears after addition of the antiauxin PCIB to the culture medium. PCIB leads to a retardation or blockage of the cell cycle during the light period of the culture. Under the influence of PCIB the amount of starch in the chloroplasts is strikingly increased, probably because of a reduction of starch degradation. Addition of sugars compensates the effect of PCIB on the cell cycle. The effects of PCIB are counteracted by auxin. The results are taken as evidence that auxin plays a role in directing the transport of substances needed for the continuation of the cell reproduction cycle between adjacent cells of the meristem.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 40
    ISSN: 1432-2048
    Keywords: Auxin ; Cambium ; Gibberellin ; Picea ; Tracheids-wood production
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The diameter and wall thickness of tracheids produced after indoleacetic acid treatment were not significantly different from those of the intact controls, for the first few weeks after treatment of disbudded shoots of Picea abies Karst. and Picea sitchensis (Bong.) Carr. However, lateral application of indoleacetic acid (IAA) to intact shoots increased both tracheid diameter and wall thickness; it is suggested that IAA acted synergistically with another endogenous growth regulator, which was also removed by disbudding. Increase in wall thickness after exogenous IAA was associated with increase in duration of the wall thickening phase of tracheid differentiation; this is discussed in relation to the seasonal change from early to latewood. Cambial dormancy was induced by disbudding during active wood production. Since this occurred with or without the presence of current leaves, it is concluded that in Picea continued cambial activity depends upon supply of auxin from the buds, and cannot be supplied from expanded leaves or from the internode itself. Neither indoleacetic acid nor gibberellic acid stimulated renewed cambial activity when applied after the cessation of wood production. With both disbudded and intact shoots, the effectiveness of exogenous IAA declined with time, probably due to decreasing penetration through callus developing at the wounded surface. It is suggested that this apparent change in IAA effectiveness may explain some discrepancies between the results of previous observers.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 41
    Electronic Resource
    Electronic Resource
    Springer
    Planta 134 (1977), S. 295-299 
    ISSN: 1432-2048
    Keywords: Abscisic acid ; Apical dominance ; Auxin ; Gibberellin ; Hormone transport ; Phaseolus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Abscisic acid (ABA) in lanolin, applied to the internode of decapitated runner bean plants enhances the outgrowth of lateral buds. The optimum concentration of the paste is 10-5 M. The effect of ABA is counteracted by indoleacetic acid (IAA) but not by gibberellic acid (GA3). There is no effect when ABA is applied to the apical bud or lateral buds of intact plants. However, 13.2 ng given to the lateral buds of decapitated plants stimulate their growth, whereas higher concentrations are inhibitory. Consequently, ABA enhances growth of lateral buds directly, but only when apical dominance is already weakened. The growth of the decapitated 2nd internode was not affected by ABA. Radioactivity from [2-14C] ABA, applied to nonelongating 2nd internode stumps of decapitated runner bean plants moves to the lateral buds, whereas [1-14C]IAA-and [3H]GA1-translocation is much weaker. ABA transport is inhibited if IAA or [3H]GA1 is applied simultaneously. In elongating internodes [14C]ABA is almost completely immobile. [14C]IAA-and [3H]GA1-translocation is not affected by ABA. The amount of radioactivity from labelled ABA, translocated to the lateral buds, is highest during the early stages of bud outgrowth.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 42
    Electronic Resource
    Electronic Resource
    Springer
    Planta 135 (1977), S. 207-212 
    ISSN: 1432-2048
    Keywords: Auxin ; Cytokinin ; Explants ; Helianthus ; Tuber (explants) ; Xylem differentiation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract the culture of Jerusalem artichoke (Helianthus tuberosus L.) tuber explants on filter paper discs moistened with liquid medium resulted in rapid and consistent xylem differentiation. The number of tracheary elements increased in discrete steps, the first at 48 h with a second at 56–58 h, following partially synchronous mitoses at 20 and 30 h. Factors favouring xylem cell differentiation were optimum levels of both an auxin and a cytokinin, low medium nitrogen concentrations, small volumes of medium, and high culture temperatures. A cell counting method employing Feulgen-stained nuclei and suitable for quantifyings small numbers of immature tracheary elements is described.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 43
    ISSN: 1432-2048
    Keywords: Key words: Actin filament ; Auxin ; Cell wall (crossed polylamellate structure) ; Gibberellin ; Microtubule (reorientation) ; Vigna (epicotyl)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract. The orientation of microtubules (MTs) was examined in epidermal cells of azuki bean (Vigna angularis Ohwi et Ohashi) epicotyls. The orientation of MTs adjacent to the outer tangential wall of the cells, which has a crossed polylamellate structure with lamellae of longitudinal cellulose microfibrils alternating with lamellae of transverse cellulose microfibrils, differed from one cell to another. Treatment with an auxin-free solution caused the accumulation of cells with longitudinal MTs and subsequent treatment with a solution that contained auxin resulted in the accumulation of cells with transverse MTs, showing that sequential treatments with auxin-free and auxin-containing solutions can synchronize the reorientation of MTs. The MTs, once reoriented from longitudinal to transverse, returned to longitudinal and then back to transverse once again, the duration of the cycle being about 6 h. Gibberellic acid, known to increase the percentage of cells with transverse MTs, promoted reorientation of MTs from longitudinal to transverse and inhibited that from transverse to longitudinal. Cytochalasin D, an agent that disrupts actin filaments, speeded up the reorientation from transverse to longitudinal and slowed down that from longitudinal to transverse. It caused an increase in the percentage of cells with MTs in mixed orientation, and the percentage of such cells was highest when the percentage of cells with longitudinal MTs was decreasing and that of cells with transverse MTs was increasing.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 44
    ISSN: 1432-2048
    Keywords: Auxin ; Cell elongation ; Epidermis peeling ; Fusicoccin ; Pisum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The effects of peeling and wounding on the indole-3-acetic acid (IAA) and fusicoccin (FC) growth response of etiolated Pisum sativum L. cv. Alaska stem tissue were examined. Over a 5 h growth period, peeling was found to virtually eliminate the IAA response, but about 30% of the FC response remained. In contrast, unpeeled segments wounded with six vertical slits exhibited significant responses to both IAA and FC, indicating that peeling does not act by damaging the tissue. Microscopy showed that the epidermis was removed intact and that the underlying tissue was essentially undamaged. Neither the addition of 2% sucrose to the incubation medium nor the use of a range of IAA concentrations down to 10-8 M restored IAA-induced growth in peeled segments, suggesting that lack of osmotic solutes and supra-optimal uptake of IAA were not important factors over this time period. It is concluded that, although the possibility remains that peeling merely allows leakage of hydrogen ions into the medium, it seems more likely that peeling off the epidermis removes the auxin responsive tissue.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 45
    ISSN: 1432-2048
    Keywords: Acidification and growth ; Auxin ; Avena ; Coleoptile ; Epidermis, peeling ; Fusicoccin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Coleoptiles of oats (Avena sativa L.) are often peeled in order to observe hormone-enhanced acidification of the external medium. It is shown by means of the scanning electron microscope that peeling largely removes a single layer of cells, the epidermis with its cuticle. Strips of intact and damaged epidermal cells remain, but most of the newly exposed surface is composed of cortical cells. The cortical face is relatively intact, except that some cells appear punctured and some are broken when a vascular bundle is pulled out with the epidermis. The surface of the cortex is covered by a thin “film” which is partially digested by 2% pectinase. The pectinase pretreatment also inhibits indoleacetic-acid- and fusicoccin-enhanced acidification. Thus, although peeling could be involved in proton extrusion, physical damage to the coleoptile cells per se does not seem to be the major stimulus leading to hormone-enhanced acidification.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 46
    ISSN: 1432-2048
    Keywords: Key words:β-1 ; 3-Glucanase ; Immunocytochemistry ; Leaf rust pathogen ; Resistance ; Triticum (pathogen resistance)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract. An antiserum raised against the purified 33-kDa β-1,3-glucanase of wheat (Triticum aestivum L.) was employed to investigate the ultrastructural localization of the enzyme in wheat leaves infected with Puccinia recondita Rob. ex Desm. f.sp. tritici Eriks. and Henn. using a post-embedding immunogold labelling technique. In both compatible and incompatible interactions, β-1,3-glucanase was detected in the host plasmalemma and in the domain of the host cell wall near the plasmalemma of the mesophyll cells, but higher concentrations of the enzyme were detected in infected resistant wheat leaves than in infected susceptible ones. β-1,3-Glucanase was also found in the secondary thickening of xylem vessels and in the walls of guard cells, epidermal cells and phloem elements, while no labelling was observed in host organelles, viz. vacuoles, mitochondria, endoplasmic reticulum, Golgi bodies, nuclei and chloroplasts. A low concentration of the enzyme was detected on the intercellular hyphal wall and in the hyphal cytoplasm. In the compatible interaction, β-1,3-glucanase was demonstrated to accumulate predominantly in the haustorial wall and extrahaustorial matrix. In the incompatible interaction, strong labelling for β-1,3-glucanase was found in host cell wall appositions, in the extracellular matrix in the intercellular space, and in electron-dense structures of host origin which occurred in the incompatible interaction only.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 47
    ISSN: 1432-2048
    Keywords: Key words: AMP-isopentenyl ; phosphotransferase ; Auxin ; Chloroplast division ; Cell differentiation ; Cytokinin - Physcomitrella
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract. Development of Physcomitrella patens (Hedw.) B.S.G. starts with a filamentous protonema growing by apical cell division. As a developmental switch, some subapical cells produce three-faced apical cells, the so-called buds, which grow to form leafy shoots, the gametophores. Application of cytokinins enhances bud formation but no subsequent gametophore development in several mosses. We used the ipt gene of Agrobacterium tumefaciens, encoding a protein which catalyzes the rate-limiting step in cytokinin biosynthesis, to transform two developmental Physcomitrella mutants. One mutant (P24) was defective in budding (bud) and thus did not produce three-faced cells, while the other one (PC22) was a double mutant, defective in plastid division (pdi), thus possessing at the most one giant chloroplast per cell, and in gametophore development (gad), resulting in malformed buds which could not differentiate into leafy gametophores. Expression of the ipt gene rescued the mutations in budding and in plastid division but not the one in gametophore development. By mutant rescue we provide evidence for a distinct physiological difference between externally applied and internally produced cytokinins. Levels of immunoreactive cytokinins and indole-3-acetic acid were determined in tissues and in culture media of the wild-type moss, both mutants and four of their stable ipt transformants. Isopentenyl-type cytokinins were the most abundant cytokinins in Physcomitrella, whereas zeatin-type cytokinins, the major native cytokinins of higher plants, were not detectable. Cytokinin as well as auxin levels were enhanced in ipt transgenics, demonstrating a cross-talk between both metabolic pathways. In all genotypes, most of the cytokinin and auxin was found extracellularly. These extracellular pools may be involved in hormone transport in the non-vascular mosses. We suggest that both mutants are defective in signal-transduction rather than in cytokinin metabolism.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 48
    ISSN: 1432-2048
    Keywords: Auxin ; Avena ; Cell elongation ; Ion uptake ; Malate synthesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The short-term effects of auxin (indole-3-acetic acid) and fusicoccin (FC) on Rb+ uptake and malate accumulation in Avena sativa L. coleoptile sections have been investigated. FC stimulates 86Rb+ uptake within 1 min while auxin-enhanced uptake begins after a 15–20-min lag period. Auxin has little or no effect on 86Rb+ uptake at external pHs of 6.0 or less, but substantial auxin effects can be observed in the range of pH 6.5 to 7.5. Competition studies indicate that the uptake mechanism is specific for Rb+ and K+. After 3 h of auxin treatment the total amount of malate in the coleoptile sections is doubled compared to control sections. FC causes a doubling of malate levels within 60 min of treatment. Auxin-induced malate accumulation exhibits a sensitivity to inhibitors and pH which is similar to that observed for the H+-extrusion and Rb+-uptake responses. Both auxin- and FC-enhanced malate accumulation are stimulated by monovalent cations but this effect is not specific for K+.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 49
    ISSN: 1432-2048
    Keywords: Abscisic acid ; Auxin ; Cambium ; Picea
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Indole-3-acetic acid (IAA) and abscisic acid (ABA) were identified by combined gas chromatography-mass spectrometry (GCMS) in fractions obtained by diffusion and extraction from bark peelings of Sitka spruce. A procedure is described for the quantitative analysis of IAA and ABA levels in the same extract using the GCMS technique of single-ion current monitoring. This procedure was used to measure the diffusible, free, and bound fractions of IAA and ABA in the cambial region of Sitka spruce throughout one year; the range in concentration for these fractions was 0.06–0.30, 0.46–3.85, and 0.04–0.20 μg/g oven-dry weight, respectively, for IAA, and 0–0.08, 0.03–2.21, and 0.13–0.66 μg/g oven-dry weight, respectively, for ABA. Movement in the cambial region was found to be polar for endogenous IAA and nonpolar for endogenous ABA. Recoveries of [14C]IAA internal standards showed that 73–99.5% of the IAA was lost during purification, and that there could be up to 5-fold differences in recovery between purifications, indicating that IAA loss shold be measured in quantitative analyses.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 50
    Electronic Resource
    Electronic Resource
    Springer
    Planta 135 (1977), S. 1-5 
    ISSN: 1432-2048
    Keywords: Auxin ; Cell elongation ; Elongation ; Root growth ; Zea
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The effect of indole-3-acetic acid (IAA) on the elongation rates of 2 mm corn (Zea mays L.) root segments induced by citrate-phosphate buffer (or unbuffered) solutions of pH 4.0 and 7.0 was studied. At pH 7.0, auxin initially reduced the elongation rate in both buffered and unbuffered solutions. Only in buffer at pH 7.0 was auxin at a concentration of 0.1 μM found to promote the elongation rate though briefly. THis promoted rate represented only ca. 20% of the rate achieved with only buffer at pH 4.0. Auxin in pH 4.0 buffered and unbuffered solutions only served to reduce the elongation rates of root segments. Some comparative experiments were done using 2 mm corn coleoptile segments. Auxin (pH 6.8) promoted the elongation rate of coleoptile segments to a level equal or greater than the maximal H ion-induced rate. The two responses of root segments to auxin are compared to auxin action in coleoptile growth.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 51
    ISSN: 1432-0878
    Keywords: Pituitary ; Dexamethasone ; ACTH ; Autoradiography ; Immunocytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary 3H-Dexamethasone (10 μg/kg) was injected intravenously in adrenalectomized rats and after survival times of 5, 30, 60, and 180 min its uptake within the pituitary was studied by autoradiography. Radioactivity was concentrated in cell nuclei in the pars nervosa and pars distalis. Within the pars intermedia, only cells of the marginal zone were labeled. In the pars distalis, some cells showed a weak nuclear accumulation of radioactivity as early as 5 min after injection. The tissue radioactivity was nearly maximal at 5 min, and the proportion of radioactivity in nuclei reached a maximum of 60–70% by 30 min. In competition experiments, non-radioactive steroids (1 mg/kg) were injected 5 min before 3H-dexamethasone and sacrifice was 30 min later. Dexamethasone markedly diminished the nuclear accumulation in the pars distalis, but corticosterone and progesterone did not. In the pars nervosa, corticosterone and progesterone competed for nuclear uptake of 3H-dexamethasone, although less effectively than dexamethasone itself. Different cell types in the pars distalis were characterized by treating autoradiograms with an immuno-peroxidase bridge procedure. Cells treated with anti-ACTH 17–39 had the greatest nuclear concentration of radioactivity, and those stained with anti-TSH were least heavily labeled. Cells treated with antisera to GH, PRL, and hCG were moderately labeled.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 52
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 178 (1977), S. 17-38 
    ISSN: 1432-0878
    Keywords: Myosin ; Immunocytochemistry ; Adrenal medulla ; Exocytosis ; Secretion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Myosin was isolated in high purity from the bovine adrenal medulla by gel filtration and ion exchange chromatography. The purified myosin was analyzed by electrophoresis in gels containing SDS and found to contain a 200,000 molecular weight heavy chain and major light chains of molecular weights 20,000 and 17,000 in a 1∶1∶1 molar ratio. At high ionic strength the myosin had high Ca-ATPase and K-EDTA-ATPase activities and low Mg-ATPase activity. At low ionic strength, the Mg-ATPase was activated to a low level by rabbit muscle actin. The myosin was found to decorate F-actin in the absence, but not the presence of ATP. In low ionic strength solutions, the myosin assembled into characteristic bipolar filaments. The distribution of this myosin in the adrenal medulla and of cross-reacting myosin in several other bovine tissues was determined with the use of antimedullary myosin immunoglobulin G as a specific stain that was detected by direct and indirect immunofluorescence. In the medulla strong staining was seen between the chords of chromaffin cells indicating the presence of a highly muscular vasculature that may perform functions analogous to those of the myoepithelium of exocrine glands. The chromaffin cells showed weak positive staining around the nuclei and in a pattern radiating toward adjacent blood vessels. Cells of the inner zone of the adrenal cortex showed strong staining in the peripheral cytoplasm while cells in the intermediate and outer zones did not stain. In a blood smear, platelets and the cytoplasm of leukocytes stained strongly while erythrocytes did not stain. In striated muscle and the gray and white matter of the cerebrum only the capillaries and larger vessels stained. In the liver the phagocytic cells bordering vascular sinuses stained strongly while the hepatocytes were separated from one another by a 2 micron trilaminar band possibly representing the microfilament web surrounding the bile canaliculi and associated with junctional complexes. The results suggest that myosin is present in several highly differentiated, non-motile tissue cells where it may play a role in secretion or other specialized functions.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 53
    Electronic Resource
    Electronic Resource
    Springer
    Fresenius' Zeitschrift für analytische Chemie 292 (1978), S. 381-384 
    ISSN: 1618-2650
    Keywords: Best. von Aminen, aromat. ; Chromatographie, Dünnschicht ; Remissionsmessung
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Es wird eine Methode zur quantitativen Bestimmung von aromatischen Aminen beschrieben. Diese werden dünnschicht-chromatographisch auf Kieselgel 60 F254 Fertigplatten in den Laufmitteln n-Propanol/Methanol/Wasser/Eisessig (65∶15∶15∶20; Vol.) oder n-Butanol/Wasser/Eisessig (66∶17∶17; Vol.) von den Begleitstoffen abgetrennt. Die getrennten Aminflecke werden entweder im Ultraviolett-Bereich oder nach Diazotierung im sichtbaren Bereich mit dem Chromatogramm-Spektralphotometer PMQ II nach der Remissionsmethode gemessen und anhand der auf derselben Platte aufgestellten Eichgerade ausgewertet. Die quantitative Bestimmung wird anhand der beiden Amine 5-Amino-2,4,6-trijod-isophthalsäurebis-(2,3-dihydroxy-propyl-N-methylamid) (I) und 2,4,6-Trijod-3-aminobenzoesäure (II) in Röntgenkontrastmittelpräparaten (RKP) demonstriert. Sowohl im UV- als auch im sichtbaren Bereich, läßt sich in 3000 μg RK-Säure (RKS) noch 0,1 μg freies aromatisches Amin, das sind 0,003%, bezogen auf die eingesetzte Menge RKS, mit einer maximalen relativen Standardabweichung von 4% bestimmen. Diese Methode ist spezifischer und empfindlicher als die der Diazotierung in Lösung.
    Notes: Summary The aromatic amines are separated from impurities by thin-layer chromatography on silica gel 60 F254 precoated plates in the mobile solvents n-propanol/methanol/water/glacial acetic acid (65∶15∶15∶20; vol.) or n-butanol/water/glacial acetic acid (66∶17∶17; vol.). The separated amine spots are measured by the remission method by means of the TLC densitometer PMQ II, either in the u.v. region or, after diazotization, in the visible region, and evaluated on the basis of the linear calibration curve set up on the same plate. Quantitative determination is demonstrated by means of the two amines, 5-amino-2,4,6-triiodoisophthalic acid-bis-(2,3-dihydroxypropyl-N-methylamide) (I) and 2,4,6-triiodo-3-aminobenzoic acid (II), in radiopaque contrast media (RCM). Both in the u.v. and visible regions, it is still possible to determine 0.1 μg of free aromatic amine in 3000 μg of radiopaque contrast medium acid (RCA), or 0.003% in terms of the amount of RCA used, with a maximum relative standard deviation of 4%. This method is more specific and more sensitive than that of diazotization in solution.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 54
    Electronic Resource
    Electronic Resource
    Springer
    Fresenius' Zeitschrift für analytische Chemie 293 (1978), S. 135-137 
    ISSN: 1618-2650
    Keywords: Analyse von Desodorantien, Phenolderivaten in Kosmetika ; Chromatographie, Dünnschicht
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Phenolische Desodorantien in kosmetischen Präparaten lassen sich durch Umsetzung mit Echtrotsalz Al (Anthrachinondiazonium-chlorid-1) in wäßrig-alkalischer Lösung, Extraktion des gebildeten Azofarbstoffes mit einem organischen Lösungsmittel und anschließender Dünnschicht-Chromatographie schnell identifizieren. In den meisten Fällen ist die Abhängigkeit zwischen der Extinktion der Farbstofflösung und der eingesetzten Menge des betreffenden Desodorants linear, wodurch dann auch quantitative Bestimmungen möglich sind.
    Notes: Summary Phenolic compounds, used as deodorants in cosmetic products can be identified quickly by reaction with anthraquinonediazonium chloride-1 (Echtrotsalz Al) in aqueous alkaline medium, extraction of the azo dye with an organic solvent and separation by thinlayer chromatography. The relation between the absorbance of the coloured solution and the concentration of the deodorant concerned is generally linear; in these cases quantitative determinations are always possible.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 55
    Electronic Resource
    Electronic Resource
    Springer
    Fresenius' Zeitschrift für analytische Chemie 291 (1978), S. 366-368 
    ISSN: 1618-2650
    Keywords: Nachw. von N-Heterocycl. Verbindungen ; Chromatographie, Dünnschicht ; CuSO4-imprägnierte Schichten, Fluorescenz
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Durch die charakteristischen Fluorescenzfarben und die Fluorescenz-Thermochromie der CuJ-Komplexe lassen sich N-Heterocyclen auf Chromatogrammen meist einwandfrei identifizieren. Eine wesentliche Vereinfachung wird durch die Verwendung CuSO4-imprägnierter Kieselgelschichten erreicht. Die Nachweisempfindlichkeiten insbesondere bei tiefer Temperatur ändern sich im Vergleich zur ursprünglichen Technik kaum.
    Notes: Summary N-Heterocycles can usually be identified with certainty through the characteristic fluorescence colours and fluorescence-thermochromism of the CuI-complexes. The use of CuSO4-impregnated silica gel layers facilitates the procedure considerably, and scarcely reduces the sensitivity of detection, particularly at low temperature.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 56
    Electronic Resource
    Electronic Resource
    Springer
    Fresenius' Zeitschrift für analytische Chemie 292 (1978), S. 415-416 
    ISSN: 1618-2650
    Keywords: Trenn. von Anorgan. Ionen ; Chromatographie, Dünnschicht ; mit p-Toluidin imprägnierte Schichten
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 57
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 186 (1978), S. 399-412 
    ISSN: 1432-0878
    Keywords: Pituitary gland ; Dog ; Pars distalis ; Thyrotropin (TSH) ; Immunocytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Using the immunoperoxidase technique and antisera to the specific beta (β) subunits of bovine and rat TSH1, selective immunocytochemical staining was localized in a specific cell population in the pars distalis of the dog pituitary gland. These TSH cells were found to be positive to aldehyde fuchsin, alcian blue, periodic acid-Schiff (PAS) and aniline blue. With the performic acidalcian blue (pH 0.2) -PAS-orange G procedure these cells stained blue-purple, demonstrating FSH/LH cells (blue or turquoise), ACTH/MSH cells (redpurple) and PRL cells (orange-red). The TSH cells were further differentiated from other functional cell types of the pars distalis on the basis of their typical cytological features, intraglandular distribution and by immunocytochemical double staining. In the pars distalis of adult male dogs the TSH cells were mostly shown to be smaller in size and less numerous than in bitches in the anestrous phase of the sexual cycle. Moreover, cytological alterations in the immunoreactive thyrotrophs in the pituitary of male and female dogs generally paralleled the spontaneous changes in thyroid function associated with thyroid atrophy and/or pituitary insufficiency, and thyroid hyperplasia or goiter. In conclusion, because of their specificity and high potency, the antisera to the β-subunits of bovine and rat TSH represent an effective tool for the selective immunocytochemical localization of TSH in the dog pituitary. This allows the study of the morphology and function of TSH cells under different physiological, pathological and experimental conditions.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 58
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 188 (1978), S. 99-106 
    ISSN: 1432-0878
    Keywords: LHRH-neurosecretion ; Avian hypothalamus ; Vasotocin neurosecretion ; Immunocytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A fluorescent technique applying specific LHRH and vasotocin antisera was used for the immunocytochemical localization of the respective neurosecretory systems in the hypothalamus of gonadectomized, testosteronetreated and/or serotonin injected male domestic ducks. An immunoreactive (IR) LHRH-producing system, with perikarya located in the preoptic nucleus, could be traced through the ventral hypothalamus down to the external layer of the rostral and caudal ME, in close vicinity to the hypophysial portal system. An IR-vasotocin system originating in the paraventricular and supraoptic nuclei ran through the ventral hypothalamus, but terminated in (i) the external layer of the rostral ME, and (ii) in the posterior lobe of the hypophysis.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 59
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 188 (1978), S. 119-132 
    ISSN: 1432-0878
    Keywords: Neurophysin ; Paraventricular nucleus ; Supraoptic nucleus ; Sheep ; Immunocytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary An antiserum cross-reactive against ovine neurophysins-I-II and -III has been used in conjunction with the immunoperoxidase histochemical procedure to localize the cells of the sheep paraventricular (PVN) and supraoptic nuclei (SON). In order to describe the topographical distribution of the SON and PVN a study was made on the serial sections cut (a) transversely from rostral to caudal positions and (b) sagittally from lateral to medial positions of the hypothalamus. The cells of the SON, when examined in the transverse aspect, extended approximately 1900 μ caudally and when examined in the sagittal plane were contained within a lateral-medial distance of 4830 μ. In each case the SON cells lay adjacent to the optic chiasm. As sections were cut transversely, the cells of the PVN first appeared in a rostral position defined as 0 μ and close to the ventral lining of the third ventricle. This general ventral and ventro-lateral distribution of cells maintained up to a caudal distance of approximately 840 μ. From positions 1260–2310 μ there was a dramatic dorsal shift of the PVN cells which by this time had also extended laterally. The total rostral-caudal distance occupied by the PVN cells was 3150 μ. That the lateral-medial distance occupied by the PVN was small (1050 μ) was determined on examining the magnocellular nuclei in sagittal section.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 60
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 205 (1980), S. 43-53 
    ISSN: 1432-0878
    Keywords: Brain ; Rana temporaria ; Somatostatin-containing neurons ; Immunocytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The brain of the frog Rana temporaria was studied at the light microscopic level with the use of a double immunocytochemical staining method. The telencephalon, diencephalon and rhombencephalon contain somatostatin perikarya and fibers. In the telencephalon, the location of the somatostatin neurons largely corresponds to that of mammals. In the hypothalamus, the somatostatin perikarya are located in and near the magnocellular preoptic nucleus and also in the pars ventralis of the tuber cinereum. Like the somatostatin neurons of the rat hypothalamus, they form a separate subpopulation, different from the neurons producing neurohypophysial hormones. In Rana, somatostatin neurons are also present in (as well as in the vicinity of) the subfornical organ, in the thalamus, the tectum opticum, the interpeduncular nucleus and the caudal end of the roof of the calamus scriptorius. A precise localization of the perikarya of most somatostatin fibers, including those found in the median eminence and the neural lobe, was not attained.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 61
    ISSN: 1432-0878
    Keywords: Key words: Neurofilaments ; Phosphorylation ; Differentiation ; Immunocytochemistry ; Brain storage ; Fixation ; Microwave ; Human
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  Neurofilaments, which are exclusively found in nerve cells, are one of the earliest recognizable features of the maturing nervous system. The differential distribution of neurofilament proteins in varying degrees of phosphorylation within a neuron provides the possibility of selectively demonstrating either somata and dendrites or axons. Non-phosphorylated neurofilaments typical of somata and dendrites can be visualized with the aid of monoclonal antibody SMI 311, whereas antibody SMI 312 is directed against highly phosphorylated axonal epitopes of neurofilaments. The maturation of neuronal types, the development of area-specific axonal networks, and the gradients of maturation can thus be demonstrated. Optimal immunostaining with SMI 311 and SMI 312 is achieved when specimens are fixed in a mixture of paraformaldehyde and picric acid for up to 3 days and sections are incubated free-floating. Neurons, with their dendritic domains immunostained by SMI 311 in a Golgi-like manner, can be completely visualized in relatively thick sections. The limitations of Golgi-preparations, such as glia-labeling, artifacts, and the staining of only a small non-representative percentage of existing neurons, are not apparent in SMI preparations, which additionally provide the possibility of selectively staining axonal networks. The results achieved in normal fetal brain provide the basis for studies of developmental disturbances.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 62
    ISSN: 1432-0878
    Keywords: Key words Annexin 5 ; Immunocytochemistry ; Pituitary ; Ovary ; Testis ; Adrenal gland ; Thyroid gland ; Rat (wistar)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  Annexin 5, a unique calcium- and phospholipid-binding protein, has been investigated for its specific distribution in rat endocrine organs by immunocytochemistry with a specific antiserum to recombinant rat annexin 5. Follicular epithelial cells and parafollicular cells of the thyroid gland, adrenocortical cells of the zona fasciculata and zona reticularis, luteal cells, testicular interstitial cells, and Sertoli cells were shown to contain annexin 5. To examine whether the synthesis of annexin 5 would be affected by a change in humoral signal, the distribution of annexin 5 in the anterior pituitary was examined three weeks after ovariectomy. The withdrawal of ovarian hormones induced huge castration cells in the anterior pituitary gland, which contained abundant annexin 5. Annexin 5 was not detected in the pineal gland, the parathyroid gland, the islet of Langerhans, the adrenal medulla, zona glomerulosa cells, and granulosa cells. Since annexin 5 was shown to exist in many of the endocrine tissues examined, to be localized in specific cell types, and to be abundant in castration cells, it is suggested that annexin 5 contributes to secretory cell functions, which may be common to endocrine cells secreting chemically different hormones.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 63
    ISSN: 1432-0878
    Keywords: Key words Co-expression of mRNAs ; Gonadotropin-releasing hormone ; Immunocytochemistry ; In situ hybridization ; Oncorhynchus nerka (Teleostei)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  The localization of two salmon-type gonadotropin-releasing hormone (sGnRH) precursors, pro-sGnRH-I (short type) and pro-sGnRH-II (long type), was investigated by using in situ hybridization techniques in the brain of the landlocked sockeye salmon, Oncorhynchus nerka. We used 30-mer oligonucleotide probes complementary to pro-sGnRH-I and pro-sGnRH-II cDNA. No significant differences were observed in the localization of sGnRH neurons expressing pro-sGnRH-I and pro-sGnRH-II mRNAs; both were expressed in the olfactory nerve, the olfactory bulbs, the regions between the olfactory bulb and telencephalon, the ventral telencephalon, the preoptic area, and the hypothalamus. Almost all sGnRH neurons examined co-expressed both precursors. The expression of two sGnRH precursors in the same neuron and the wide distribution of such neurons in the brain suggest that there are no functional differences between the two precursors.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 64
    ISSN: 1432-0878
    Keywords: Key words Pancreas ; exocrine ; Hibernation ; Amylase ; Immunocytochemistry ; Muscardinus avellanarius (Rodentia)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Pancreatic acinar cells of euthermic, hibernating and arousing individuals of the hazel dormouse Muscardinus avellanarius (Gliridae) have been observed at the electron-microscopic level and analysed by means of ultrastructural morphometry and immunocytochemistry in order to investigate possible fine structural changes of cellular components during periods of strikingly different degrees of metabolic activity. During hibernation, the cisternae of the rough endoplasmic reticulum (RER) flatten assuming a parallel pattern, the Golgi apparatus is extremely reduced and the mitochondria contain many electron-dense particles. The cell nuclei appear irregularly shaped, with deep indentations containing small zymogen granules. They also contain abundant coiled bodies and unusual constituents, such as amorphous bodies and dense granular bodies. Large numbers of zymogen granules occur in all animals. However, the acinar lumina are open and filled with zymogen only in euthermic animals, whereas, in hibernating and arousing individuals, they appear to be closed. Morphometrical analyses indicate that, in pancreatic acinar cells, nuclei and zymogen granules significantly decrease in size from euthermia to hibernation, probably reflecting a drastic decrease of metabolic activities, mainly protein synthesis and processing. In all the studied animals, immunocytochemistry with specific antibodies has revealed an increasing gradient in α-amylase content along the RER-Golgi-zymogen granule pathway, reflecting the protein concentration along the secretory pathway. Moreover, during deep hibernation, significantly larger amounts of α-amylase accumulate in RER and zymogen granules in comparison to the other seasonal phases analysed. Upon arousal, all cytoplasmic and nuclear constituents restore their euthermic aspect and all morphometrical and immunocytochemical parameters exhibit the euthermic values, thereby indicating a rapid resumption of metabolic activities.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 65
    ISSN: 1432-0878
    Keywords: Key words Adrenomedullin ; Pancreas ; Development ; Immunocytochemistry ; Colocalizations ; Rat (Sprague Dawley)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  Adrenomedullin is an α-amidated 52-amino acid peptide involved in many physiological actions, among others the regulation of insulin secretion. Using immunohistochemical methods, we found that adrenomedullin immunoreactivity first appears at day 11.5 of embryonic development in the rat, coinciding with the appearance of pancreatic glucagon. The early appearance of adrenomedullin in the developing pancreas may indicate an active involvement in either the morphogenesis of the organ or its endocrine/paracrine/autocrine hormone regulation during intrauterine life. We also investigated the pattern of colocalizations of adrenomedullin with the other pancreatic hormones. At some point during development all the cell types express adrenomedullin, progressively evolving towards the adult pattern where only the pancreatic polypeptide cells contain a strong immunoreactivity for adrenomedullin. At this point the remaining cells of the islet are, in general, weakly stained. This sequential and time-dependent expression of adrenomedullin suggests a tight regulation similar to that observed for other modulatory substances responsible for embryonic morphogenesis.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 66
    ISSN: 1432-0878
    Keywords: Key words Fish ; Zebrafish ; Immunocytochemistry ; Keratin ; Cytoskeleton ; Danio rerio (Teleostei)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  We have identified a number of type I and type II keratins in the zebrafish Danio rerio by two-dimensional polyacrylamide gel electrophoresis, complementary keratin blot-binding assay and immunoblotting. These keratins range from 56 kDa to 46 kDa in molecular mass and from pH 6.6 to pH 5.2 in isoelectric point. Type II zebrafish keratins exhibit significantly higher molecular masses (56–52 kDa) compared with the type I keratins (50–48 kDa), but the isoelectric points show no significant difference between the two keratin subclasses (type II: pH 6.0–5.5; type I: pH 6.1–5.2). According to their occurrence in various zebrafish tissues, the identified keratins can be classified into “E” (epidermal) and “S” (simple epithelial) proteins. A panel of monoclonal anti-keratin antibodies has been used for immunoblotting of zebrafish cytoskeletal preparations and immunofluorescence microscopy of frozen tissue sections. These antibodies have revealed differential cytoplasmic expression of keratins; this not only includes epithelia, but also a variety of mesenchymally derived cells and tissues. Thus, previously detected fundamental differences in keratin expression patterns between higher vertebrates and a salmonid, the rainbow trout Oncorhynchus mykiss, also apply between vertebrates and the zebrafish, a cyprinid. However, in spite of notable similarities, trout and zebrafish keratins differ from each other in many details. The present data provide a firm basis from which the application of keratins as cell differentiation markers in the well-established genetic model organism, the zebrafish, can be developed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 67
    ISSN: 1432-0878
    Keywords: Key words Histamine ; Immunocytochemistry ; Mast cells ; Melanocytes ; Nerves ; Rana esculenta (Anura)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  The number, distribution, and ultrastructural characteristics of mast cells were assessed in the tongue, heart, and kidney of the frog Rana esculenta. The density of tongue mast cells (253±45 mast cells/mm2) was significantly higher than that of the heart (5.3±0.4/mm2) and kidney (15.3±1.4 /mm2). A striking feature of this study was the remarkable association of frog mast cells to nerves. The ultrastructural study of the mast cell/nerve association demonstrated that mast cells were closely apposed to or even embedded in nerves. Mast cells were also physically associated with melanocytes even in the heart. Mast cells were Alcian blue+/safranin+ in the tongue and in the peritoneum, whereas in the heart and in the kidney they were Alcian blue–/safranin+. The mast cells in the lamina propria of the gastrointestinal tract were Alcian blue+/safranin–. The cytoplasm of frog mast cells was packed with numerous heterogeneous, membrane-bound granules. The ultrastructure of these cytoplasmic granules was unique, being totally unlike any other previously described granules in other animal species as well as in man. The histamine content/frog mast cell (≈0.1 pg/cell) was approximately 30 times lower than that of human mast cells isolated from different tissues (≈3 pg/cell). A monoclonal anti-histamine antibody was used to confirm the ultrastructural localization of histamine in secretory granules in frog mast cells.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 68
    ISSN: 1432-0878
    Keywords: Key words Pancreas ; Stomach ; Duodenum ; Ribonuclease protection assay ; Immunocytochemistry ; Protease ; Rat ; (Sprague Dawley)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  Prior studies have revealed the presence of chymotrypsinlike protease in peripheral organs, although no definitive evidence for the synthesis of this enzyme in tissue other than the pancreas is available. In an attempt to detect chymotrypsinogen mRNA in peripheral organs, a fragment of the pancreatic chymotrypsin mRNA from rat was amplified using PCR. The sequence was identified as a portion of the rat chymotrypsin B gene overlapping exon 5 through exon 7. It was subcloned into the pGEM-4Z vector and used as a template for the vitro transcription of an antisense riboprobe. Using ribonuclease protection and Northern blot analyses, chymotrypsin mRNA was detected in the rat pancreas, stomach, duodenum, ovary, and spleen. Monoclonal and polyclonal antisera against chymotrypsin detected chymotrypsinlike immunoreactivity in rat and human pancreas, rat stomach, duodenum and jejunum. Electrophoresis and immunoblotting revealed chymotrypsin-chymotrypsinogen bands (25–29 kDa) in the stomach and duodenum. Synthesis of a potent protease such as chymotrypsin in tissue other than pancreas is significant, suggesting a potential physiological and/or pathological role in these tissues.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 69
    ISSN: 1432-0878
    Keywords: Key words Acrosome ; Epididymal maturation ; Monoclonal antibody ; Immunocytochemistry ; Spermatozoa ; Guinea pig
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  We have previously shown that a 90-kDa intra-acrosomal antigen, MN7, is restricted to the anterior acrosomal region of mouse, rat, and hamster spermatozoa. The present study has examined the localization and the behavior of MN7 during sperm maturation in the epididymis of the guinea pig by immunoelectron microscopy. MN7 showed not only a specific localization in the apical segment of the guinea pig sperm acrosome, but also a distinct alteration during maturation, as follows. MN7 was exclusively found both at the dorsal matrix and on the outer acrosome membrane (OAM)/matrix-associated materials in the apical segment. MN7 was initially distributed throughout the electron-lucent dorsal matrix in immature sperm but, during maturation, became more restricted to the spherical bodies within the electron-lucent area. MN7 on OAM/matrix-associated materials was first distributed along the ventral margin and the small area posterior to the dorsal matrix but, during maturation, disappeared from the ventral margin and became restricted to the dorsal region. These results indicate that MN7 is a good tool for studying the stepwise maturation of epididymal spermatozoa.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 70
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 206 (1980), S. 355-365 
    ISSN: 1432-0878
    Keywords: LRH neurons ; Prosimians (Tupaia, Galago) ; Fluorescence ; microscopy ; Immunocytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Reactive LRH neurons were characterized in prosimians (Tupaia and Galago) by immunofluorescence using rabbit immunesera against unconjugated synthetic LRH, or LRH conjugated with bovine serum albumin. These neurons, which vary individually in number in one species, are mainly concentrated in the rostral hypothalamus (medial preoptic area and anterior hypothalamic area) and in the lamina terminalis. In contrast to the simians and man, immunoreactive perikarya were not routinely found in the mediobasal hypothalamus of the prosimians investigated in the present study. Reactive axons of the hypothalamo-hypophyseal tract are more numerous and conspicuous in the retrochiasmatic area and in the postinfundibular eminence. They give rise to radiating collaterals ending mainly around the capillaries of the primary portal plexus of the median eminence and of the infundibular stem (where they are generally more numerous). Reactive axons of the preopticoterminal tract, originating from the perikarya of the lamina terminalis, end around the capillaries of the vascular organ or below and between the ependymal cells lining its ventricular side. In Galago a small but very distinct tract of reactive axons runs under the optic chiasma, between the lamina terminalis and the ventral labium of the infundibulum. Very fine reactive extrahypothalamic axons were observed in the posterior part of the habenular ganglia, along the preamygdaloid portion of the stria terminalis and along the blood vessels of the parolfactory area.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 71
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 211 (1980), S. 331-343 
    ISSN: 1432-0878
    Keywords: Gut hormones ; Endocrine cells ; Electron microscopy ; Immunocytochemistry ; Peptidergic innervation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Histological, cytochemical and immunocytochemical methods were used in light and electron microscopical studies to demonstrate the presence of a neuroendocrine system in the gut of the urodele, Salamandra salamandra. Cytochemical stains capable of detecting peptide-producing endocrine cells demonstrate cells reacting with Masson's silver (argentaffin) method, Grimelius' argyrophil silver method, masked metachromasia method and the lead haematoxylin stain. Using antisera raised to a variety of mammalian gut peptides, cells containing bombesin-, gastrin-, somatostatin-, substance P- and glucagon-like immunoreactivity were identified; vasoactive intestinal polypeptide- and substance P-like immunoreactivities were found in nerve fibres in the submucous and myenteric plexus. No immunoreactivity was detected for motilin, gastric inhibitory polypeptide, cholecystokinin or secretin. The ultrastructure of the immunoreactive cells and nerves was revealed by the semithin/thin method. All the cells identified contained numerous electrondense secretory granules, which varied in their chracteristic morphological structure from one cell type to another. The evidence collected in this study indicates that a complex neuroendocrine system regulating gut function is present in this amphibian and may have developed prior to the emergence of the phylum.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 72
    ISSN: 1432-0878
    Keywords: Key words Pepsinogen C ; Ontogeny ; Mucous neck cell ; Chief cell ; Intermediate mucopeptic cell ; Immunocytochemistry ; In situ hybridization ; Rat (Wistar)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  The ontogeny of pepsinogen C-producing cells in rat fundic glands was studied by means of light and electron microscopy using an antiserum raised against a synthetic peptide based on rat pepsinogen C. To confirm the immunocytochemistry results, the expression of rat pepsinogen C messenger RNA (mRNA) in the fundic gland was also examined by in situ hybridization using a digoxigenin-labeled RNA probe. In adult rats, pepsinogen C was produced by chief cells, mucous neck cells, and intermediate mucopeptic cells. Pepsinogen C-producing cells appeared in embryos as early as 18.5 days’ gestation. The development of these cells could be classified into four stages: (1) 18.5 days’ gestation to 0.5 days after birth; (2) 0.5 days to 2 weeks after birth; (3) 3–4 weeks after birth; (4) 4–8 weeks after birth. In embryos and young animals, pepsinogen C-producing cells were mucopeptic cells. By 4 weeks after birth, mucous neck cells could be distinguished morphologically. The maturation stages of the chief cells could be traced by electron microscopy along the longitudinal axis of the rat fundic gland by double-staining with anti-pepsinogen C antibody and periodic acid-thiocarbohydrazide-silver proteinate. Positive reactions for pepsinogen C and pepsinogen C mRNA expression were detected in mucous neck cells. Therefore, we conclude that mucous neck cells are precursor cells of chief cells. Mucous neck cells, intermediate cells, and chief cells are in the same differentiating cell lineage.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 73
    ISSN: 1432-0878
    Keywords: Key words Salmon GnRH ; Chicken GnRH ; II ; Radioimmunoassay ; Immunocytochemistry ; In situ hybridization ; Oncorhynchus masou (Teleostei)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  Ontogenic development of salmon gonadotropin-releasing hormone (GnRH) and chicken GnRH-II systems in masu salmon (Oncorhynchus masou) was examined. Salmon GnRH was first detected by radioimmunoassay in the embryo on day 36 after fertilization. Salmon GnRH-immunoreactive fibers were detected initially by immunocytochemistry in the vicinity of the olfactory placode of the embryo (day 36) and were distributed widely in the brain as well as in the pituitary gland of fish just after hatching (day 80). Salmon GnRH-immunoreactive neuronal somata were first detected about 6 months after fertilization in the rostroventral brain area, ranging from the olfactory nerve to the preoptic area. Salmon GnRH neuronal somata were detected earlier by in situ hybridization than by immunocytochemistry. Neuronal somata expressing salmon GnRH mRNA were first detected in the vicinity of the olfactory epithelium on day 40 and then were seen to be migrating from the olfactory epithelium, along the olfactory nerve, on day 60 and in the transitional area between olfactory nerve and olfactory bulb on day 80. In the brain, these neurons were first detected in the ventral olfactory bulb on day 80, and thereafter they were also detected in the caudal brain regions. The chicken GnRH-II system was detected later than the salmon GnRH system; chicken GnRH-II was first detected by radioimmunoassay on day 57, and chicken GnRH-II-immunoreactive fibers were first detected on day 67. Chicken GnRH-II-immunoreactive neuronal somata were not detected during the observation period. These results suggest that salmon GnRH neurons derive from the olfactory placode and then migrate into the brain and that salmon GnRH is synthesized before chicken GnRH-II.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 74
    ISSN: 1432-0878
    Keywords: Key words Enteric nervous system ; Somatostatin ; Immunocytochemistry ; Intestinal motility ; Synaptic connections ; Guinea-pig
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  Somatostatin immunoreactivity occurs in a specific subgroup of cholinergic descending interneurons in the myenteric plexus of the guinea-pig small intestine. In the present work, we made light- and electron-microscopic investigations of chemically defined inputs to these neurons, in order that the origins of the connections of other neurons with them could be deduced. Somatostatin-immunoreactive synapses and close contacts were found on the cell bodies and filamentous processes of somatostatin neurons; these were 84% of all inputs. It is thus confirmed that this class of interneuron forms chains that project anally. Descending interneurons with immunoreactivity for nitric oxide synthase provided 14% of inputs to somatostatin-immunoreactive descending interneurons. An antiserum against a calcium-binding protein, calbindin, was used as marker for the majority of intrinsic primary afferent neurons, AH/Dogiel type II neurons; this class of neurons provided only 2.5% of the inputs to somatostatin-immunoreactive descending interneurons. We conclude that somatostatin-immunoreactive descending interneurons are involved in the conduction of impulses distally along the full length of the small intestine, but receive only a minor input from calbindin-immunoreactive primary afferent neurons.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 75
    ISSN: 1432-0878
    Keywords: Key words Insect nervous system ; Immunocytochemistry ; Neural development ; Neuropeptide ; Neurohormone ; Locustatachykinin ; Spodoptera litura (Insecta)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  Neuropeptides with similarities to vertebrate tachykinins, designated tachykinin-related peptides (TRPs), have been identified in several insect species. In this investigation we have utilized an antiserum raised to one of the locust TRPs, locustatachykinin-I (LomTK-I), to determine the distribution pattern of LomTK-like immunoreactive (LTKLI) neurons in the developing nervous system of the moth Spodoptera litura. A number of LTKLI neurons could be followed from the larval to the adult nervous system: a set of median neurosecretory cells (MNCs) in the brain, a pair of brain descending neurons and a few sets on neurons in the ventral nerve cord. The distribution of LTKLI neurons in the adult brain is very similar to that seen in other insect species with prominent arborizations in the central body, antennal lobes, mushroom body calyces, optic lobe neuropils and other distinct neuropil areas in the protocerebrum and tritocerebrum. A new finding is the presence of LTKLI neurosecretory cells with axon terminals in the anterior aorta and corpora cardiaca, suggesting for the first time a neurohormonal role of tachykinin-related peptide(s) in insects. During postembryonic development the number of LTKLI neurons in the ventral nerve cord decreases somewhat, whereas the number increases in the brain. Thus the functional roles of TRPs may change to some extent during development.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 76
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 188 (1978), S. 259-264 
    ISSN: 1432-0878
    Keywords: Hypothalamus ; Human fetus ; Oxytocin ; Neurophysin ; Immunocytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The use of antibodies against oxytocin or neurophysin enabled the detection by immunocytochemistry of oxytocin-neurophysin neurons in the hypothalamus in the human fetus. The perikarya of these neurons are located in the paraventricular and supraoptic nuclei. Immunoreactive neurons occur in the median eminence. The neurophysin immunoreactive neurons were more numerous than the oxytocin immunoreactive neurons. The specificity of the immunocytological reaction was controlled. The first oxytocin-neurophysin neurons are seen as early as the 14th week of gestation.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 77
    ISSN: 1432-0878
    Keywords: Hypothalamus (rat) ; Differentiation ; Transplant ; Histofluorescence ; Immunocytochemistry ; Autoradiography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Hypothalamic tissue from 16 to 18-day fetal rats was transplanted onto the choroidal pia overlying the superior colliculus in adult female rats. After survival periods of 2 weeks to 19 months, brains containing transplants were processed for monoamine fluorescence histochemistry, immunohistochemistry for three neuropeptides (LHRH, somatostatin, neurophysin), or for autoradiography in ovariectomized hosts that received [3H] estradiol. Most of the transplants survived and retained or increased in size; 14 of 25 transplants examined by fluorescence histochemistry were found to contain median eminence-like structures. In almost all of the transplants that were stained for neuropeptides, beaded processes and occasional cell bodies were observed. Although immunoreactive fibers were found near blood vessels, no palisade arrangement typical of the normal median eminence was evident. Each of the hypothalamic transplants on which steroid autoradiography was performed contained clusters of estrophilic neurons, the intensity of labeling of which was comparable to that seen in the host hypothalamus. These results indicate that many characteristic morphological and chemical features of the hypothalamus, which are not evident in the 16 to 18-day fetus, are elaborated in transplants during the survival period in the host. Transplantation of fetal hypothalamus to adult choroidal pia thus appears to be a valuable approach for studying the factors, humoral or neural, that regulate the differentiation of this brain region.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 78
    ISSN: 1432-0878
    Keywords: Lipolytic peptide B ; Pituitary ; ACTH/MSH cells ; Brain ; Immunocytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Several lipid-mobilizing peptides occur in the pituitary, among them β-lipotropin and “lipolytic peptide A and peptide B”. The latter two peptides are distinct from β-lipotropin and appear to be chemically related to the neurophysins. Immunohistochemistry has now revealed that the lipolytic peptide B of the pituitary is localized in the ACTH- and MSH-cells. In addition, immunoreactive peptide B was found in axons of the posterior lobe of the pituitary. Immunoreactive peptide B was found also in nerve fibers and nerve cell bodies in the hypothalamus, particularly in the hypothalamo-hypophyseal tract and in the magnocellular neuronal system. Immunoreactive nerve fibers were numerous also in the periventricular nucleus of the thalamus. The antiserum against peptide B cross-reacts with neurophysin I, and hence, it cannot be excluded that at least part of the immunostaining in the brain reflects the presence of the latter component. However, the regional distribution of immunoreactive peptide B and neurophysin was not identical. Therefore, it is possible that authentic peptide B occurs not only in the pituitary but also in the brain.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 79
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 293 (1998), S. 245-252 
    ISSN: 1432-0878
    Keywords: Key words Synaptic-like microvesicles ; Synaptophysin ; Synaptobrevin ; Immunocytochemistry ; Immunoelectron microscopy ; Meriones unguiculatus (Rodentia)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  Mammalian pinealocytes contain several synaptic membrane proteins which probably play a role in the targeting and exocytosis of secretory vesicles, in particular of synaptic-like microvesicles (SLMVs). The latter are considered as the endocrine equivalent of neuronal synaptic vesicles. By means of immunocytochemical techniques and immunoblot analyses, we now show that two further key components of the molecular apparatus regulating neurotransmitter release are present in the gerbil pineal gland, i.e., munc-18–1 and cysteine string protein (csp). In addition to varicosities of nerve fibres, munc-18–1 and csp could be localized to pinealocytes where both proteins were markedly enriched in process swellings. When using antibodies against csp for an immunogold electron-microscopic study of pinealocytes, gold particles consistently decorated profiles of pleomorphic SLMVs. Interestingly, we found that also the cytosolic protein munc-18, which is partially recruited to the plasmalemma in neurons, was associated to a significant extent with SLMVs of pinealocytes and synaptic vesicles of neurons, respectively. This localization implies that munc-18 at least partially exerts its regulatory functions while being bound to secretory vesicle membranes. Our results indicate that in endocrine cells such as pinealocytes the synaptic proteins munc-18–1 and csp play essential roles during the life cycle of SLMVs.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 80
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 293 (1998), S. 349-355 
    ISSN: 1432-0878
    Keywords: Key words Germ cells ; Nucleus ; Ribonucleoproteins ; Immunocytochemistry ; Rabbit
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  The convoluted cords present in the nuclei of rabbit primary spermatocytes and spermatids differ from previously described nuclear bodies. They are composed of proteic strands decorated with granules and, in most cases, are embedded in clusters of interchromatin granules. They are partly sensitive to trypsin and can be visualised with protein-specific stains. The decorating granules are similar in size and aspect to interchromatin granules. However, only the latter are continuously immunolabelled with anti-snRNPs (small ribonucleoproteins) antibodies during spermatogenesis. The complexity and organisation of the convoluted cords are modified specifically during cell differentiation. They might be involved in the storage, transport and release of interchromatin granules in male germ cells.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 81
    ISSN: 1432-0878
    Keywords: Key words Electron microscopy ; F-actin ; Freeze-fracture ; Immunocytochemistry ; Water permeability ; Antidiuretic hormone ; Urinary bladder ; Rana temporaria (Anura)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  Electron and confocal microscopy, using immunocytochemical methods, was employed to assess osmotic water permeability of the frog (Rana temporaria) urinary bladder during transcellular water transport, induced by antidiuretic hormone (ADH) or by wash-out of autacoids from serosal, ADH-free Ringer solution. The increase of osmotic water permeability of the urinary bladder was accompanied by relevant ultrastructural changes, the most remarkable being: (1) the appearance of aggregates of intramembranous particles in the apical membrane of granular cells, and the extent of the membrane area covered by the aggregates proportional to that of the water flow; (2) redistribution of actin filaments in the cytoplasm of granular cells; judging from the anti-actin label density, the number of actin filaments in the apical region of cytoplasm was reduced by 2.5–4 times compared with normal; (3) a decrease in the total electron density of the cytoplasm due to the increased water content of granular cells.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 82
    ISSN: 1432-0878
    Keywords: Key words Plant lectins ; Epithelial cells ; Immunocytochemistry ; Autoradiography ; Immunoelectron microscopy ; Potato leafhopper ; Empoasca fabae (Insecta)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract To identify the means by which phytohemagglutinin (PHA) exerts its toxicity on the potato leafhopper, four different methods (thick and semi-thin sectioning combined with immunofluorescent staining, in vitro receptor autoradiography, and immunoelectron microscopy) were used to elucidate the PHA target tissue, binding site, and its effects on this tissue. Sixteen 1- or 2-day-old female potato leafhoppers were fed for 36 h on each of three treatments: a control, diet or a diet containing either the PHA-E subunit or the PHA-L subunit. The PHA-E subunit, but not PHA-L, had previously been shown to be lethal. The insects were then prepared for both light and confocal microscopy. Analysis of images showed that PHA bound only to the surface of midgut epithelial cells of the potato leafhopper. PHA-E caused severe disruption, disorganization, and elongation of the brush border microvilli, and swelling of the epithelial cells into the lumen of the gut, leading to complete closure of the lumen. Furthermore, PHA-E stimulated the division of midgut epithelial cell nuclei, leading to two nuclei in each cell. Nuclei later elongated and degraded. In contrast, PHA-L had little effect on the epithelial cells of the midgut. It did not strongly bind to the surface of epithelial cells and caused much less disruption of brush-border microvilli, less disorganization of the cells and less elongation of nuclei. Strong binding of PHA occurred solely on the cell membrane of the brush border microvilli of epithelial cells. In contrast, the controls (i.e., midgut tissue, blocking agent, PHA, and antibodies) showed that midgut tissue was not autofluorescent and showed no fluorescent binding signal. Analysis of both bright- and dark-field images obtained by autoradiography and immunoelectron microscopy confirmed these findings.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 83
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 185 (1977), S. 465-479 
    ISSN: 1432-0878
    Keywords: Somatostatin cells ; Pancreas ; Gut ; Immunocytochemistry ; Comparative study
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Somatostatin cells are numerous in the pancreas and digestive tract of mammals as well as birds. In the pancreas of chicken, cat and dog they occur in both the exocrine parenchyma and in the islets. In the rat and rabbit, somatostatin cells have a peripheral location in the islets, whereas in the cat, dog and man the cells are usually more randomly distributed. In the stomach of rabbits and pigs, somatostatin cells are more numerous in the oxyntic gland area than in the pyloric gland area, whereas the reverse is true for the cat, dog and man. In the cat, pig and man, somatostatin cells are fairly numerous in the duodenum, whereas in the rat, rabbit and dog they are few in this location. In the remainder of the intestines somatostatin cells are few but regularly observed. Somatostatin cells are numerous in the human fetal pancreas and gut. In the fetal rat, somatostatin cells first appear in the pancreas and duodenum (at about the 16–17th day of gestation) and subsequently in the remainder of the intestine. Somatostatin cells do not appear in the gastric mucosa until after birth. Three weeks after birth, somatostatin cells show the adult frequency of occurrence and pattern of distribution. In the chicken, somatostatin cells are numerous in the proventriculus, absent from the gizzard, abundant in the gizzard-duodenal junction (antrum), infrequent in the duodenum and virtually absent from the remainder of the intestines. No immunoreactive cells can be observed in the thyroid of any species nor in the ultimobranchial gland of the chicken. In the chick embryo, somatostatin cells are first detected in the pancreas and proventriculus (at about the 12th day of incubation). They appear in the remainder of the gut much later, in the duodenum at the 16th day, in the antrum at about the 19th day and still later in the lower small intestine. The ultrastructure of the somatostatin cells was studied in the chicken, rat, cat and man; the cells were identified by the consecutive semithin/ultrathin section technique. The somatostatin cells display the properties of the D cell. There was no difference in granule ultrastructure between somatostatin cells in the gut and the pancreas. The granules, which are the storage site of the peptide, are round, supplied with a tightly fitting membrane and have a moderately electron-dense, fine-granulated core. The mean diameter of the somatostatin granules is smallest in rat (155–170 nm) and largest in the chicken (270–290 nm).
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 84
    ISSN: 1432-0878
    Keywords: Pancreatic polypeptide (PP)-like material ; Immunocytochemistry ; Neuropeptides ; Neurosecretory cells ; Calliphora erythrocephala
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The brain of the blowfly, Calliphora erythrocephala, has been studied by means of the peroxidase-antiperoxidase immunocytochemical method, with the use of antibodies to bovine pancreatic polypeptide (BPP). A number of immunoreactive neurones have been localised, some corresponding to neurones previously identified tentatively as neurosecretory. This finding is further evidence that biologically active peptides, previously considered to be “vertebrate”, also exist in invertebrates. It also supports the concept of their evolutionary origin in nervous tissue.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 85
    ISSN: 1432-0878
    Keywords: Mesotocin neurons ; Vasotocin neurons ; Avian hypothalamus ; Preoptic area ; Immunocytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The neurosecretory systems producing mesotocin (MT) and vasotocin (VT) (the avian homologues of oxytocin and vasopressin, respectively) were characterized in the brains of the domestic mallard and Japanese quail by means of indirect immunofluorescence techniques using specific antisera. In the anterior preoptic region, including the organum vasculosum of the lamina terminalis, and at different levels of the supraoptic and paraventricular nuclei, separate mesotocin- and vasotocin-producing neurons were identified. Mesotocinergic and vasotocinergic neurons were also located in the tuberomammillary area, among the ectomammillary tract fibers. The supraoptico-neurohypophysial tract, formed by vasotocin- and mesotocincontaining axons, enters the internal zone of the median eminence and ends in the posterior lobe of the pituitary. The external zone of the rostral median eminence appears to contain vasotocin and mesotocin fibers, which terminate in close contact with the capillaries of the hypophysial portal system.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 86
    ISSN: 1432-0878
    Keywords: Key words Enamelin ; Immunocytochemistry ; Amelogenesis ; Tooth development ; Enamel ; Pig
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  Enamelins comprise an important family of the enamel matrix proteins. Porcine tooth germs were investigated immunochemically and immunocytochemically using two antibodies: a polyclonal antibody raised against the porcine 89-kDa enamelin (89 E) and an affinity purified anti-peptide antibody against the porcine enamelin amino-terminus (EN). Immunochemical analysis of layers of immature enamel from the matrix formation stage detected immunopositive protein bands ranging from 10 kDa to 155 kDa in the outer layer enamel sample irrespective of the antibodies used. In contrast, the middle and inner enamel layer mainly contained lower molecular weight enamelins. In immunocytochemical analyses of the differentiation stage, 89 E stained enamel matrix islands around mineralized collagen fibrils of dentin, while EN stained both enamel matrix islands and stippled material. At the matrix formation stage, both antibodies intensely stained enamel prisms located in the outer layer. In the inner layer, 89 E moderately stained enamel matrix homogeneously, while EN primarily stained the prism sheath. The intense immunoreaction over the surface layer of enamel matrix at the matrix formation stage, following staining with 89 E and EN, disappeared by the end of the transition stage and the early maturation stage, respectively. The Golgi apparatus and secretory granules in the ameloblasts from the late differentiation stage to the transition stage were immunostained by both antibodies. These results suggest that expression of enamelin continues from late differentiation to the transition stage and the cleavage of N-terminal region of enamelin occurs soon after secretion. Some enamelin degradation products, which apparently have no affinity for hydroxyapatite crystals, concentrate in the prism sheaths during enamel maturation.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 87
    ISSN: 1432-0878
    Keywords: Key words Mammalian-type thyrotropin ; Pituitary ; Immunocytochemistry ; Australian lungfish ; Neoceratodus forsteri (Dipnoi)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The binding sites of polyclonal antisera raised against the β-subunit of human thyroid-stimulating hormone (hTSHβ), hTSH, and ovine TSH (oTSH) have been localized in the pituitary gland of the Australian lungfish, Neoceratodus forsteri, using light microscopy. Reactivity toward anti-TSH antiserum was demonstrated in a slightly elongated and irregularly-shaped distinct cell type forming clusters in the dorso-central and ventral regions of the distal lobe. Their granules react with alcian blue (AB), and with periodic acid–Schiff (PAS), and after AB-PAS-orange G they stain blue or purple. The specificity of the different antisera was established by liquid-phase absorptions and confirmed in positive and negative tissue control systems. Our observations confirm that dipnoan (Neoceratodus) TSH shares a number of antigenic determinants with those of mammalian TSHβ and support the concept that mammalian TSHβ, or part of it, was established early in evolution, and that dipnoans (Neoceratodus) as living sarcopterygians may have an ancestor in common with the early amphibians. The mapping and detailed description of TSH-like immunoreactive cells may furnish a background to facilitate current and future analysis of the ontogeny and time course of TSH production and release in Neoceratodus in relation to different physiological conditions.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 88
    ISSN: 1615-6102
    Keywords: 2,4-Dichlorophenoxyacetic acid ; Auxin ; Carya illinoinensis ; Embryo induction ; Naphthaleneacetic acid ; Somatic embryogenesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Somatic embryos produced in vitro may exhibit structural abnormalities that affect their subsequent germination and conversion into plants. To assess the influence of auxin type on embryo initiation and development, a morphological and histological comparison was made of pecan (Carya illinoinensis) somatic embryogenic cultures induced on media with naphthaleneacetic acid or 2,4-dichlorophenoxyacetic acid (2,4-D), using light and scanning electron microscopy. Both auxins promoted enhanced cell division, particularly in subepidermal cell layers. However, notable differences were observed in mitotic activity, location of embryogenic cell proliferation, epidermal continuity, callus growth, and embryo morphology. Cultures induced on naphthaleneacetic acid had embryogenic regions composed of homogeneous, isodiametric, meristematic cells. Embryos derived from these cultures generally had a normal morphology, were single, and had a discrete apical meristem. In contrast, tissues induced on media with 2,4-D had more intense and heterogeneous regions of cell division. Proliferating cell regions were composed of meristematic cells interspersed with callus and involved more extensive regions of the mesophyll. Marked callus proliferation caused epidermal rupture in some areas. Embryos induced on medium with 2,4-D had a higher incidence of abnormalities that included fasciated, fan-shaped, and tubular embryos. Defined apical meristems were often lacking or partially obliterated due to callus proliferation. The heterogeneous, often intensive proliferation of cells in cultures induced with 2,4-D may interfere with normal patterns of embryo development.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 89
    Electronic Resource
    Electronic Resource
    Springer
    Molecular genetics and genomics 258 (1998), S. 479-487 
    ISSN: 1617-4623
    Keywords: Key words Polygalacturonase genes ; Tomato ; Abscission ; Ethylene ; Auxin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Recently, three polygalacturonase (PG) cDNAs (TAPG1, TAPG2, and TAPG4) were identified in a library prepared from tomato (Lycopersiconesculentum cv. Rutgers) leaf abscission zones. Genomic clones encoding these three cDNAs have been identified. Moreover, the genomic clones include three additional PG genes, TPG3, TAPG5 and TPG6, which have not been previously reported. A transcript for TAPG5 was detected in the RNA from leaf and flower abscission zones; however, transcripts for TPG3 and TPG6 were not. DNA sequence analysis revealed that TAPG1, TAPG2, and TPG3 are linked in a close tandem array. TAPG4, TAPG5 and TPG6 are also closely linked to each other but in divergent and inverted orientations and are not closely linked to TAPG1, TAPG2, or TPG3. TAPG4, TAPG5 and TPG6 map to the middle of chromosome 12. TPG6 contains two introns. The other five PG genes include four exons and three introns. The relative positions of introns 1 and 2 are shared by all six PG genes. The position of intron 3 is conserved in the other five. The structure of the tomato fruit PG gene, which contains 8 introns, is compared with that of the six PG genes described above. Of interest is an approximately 300 bp inverted repeat found in TAPG1, TAPG2 and TAPG4 that shares significant sequence identity with sequence in the first intron of the tomato anionic peroxidase gene, tap1. RNA blot analysis indicates that the transcript for an anionic peroxidase increases during abscission. In addition, a 250 bp sequence found in TPG3 shares high sequence identity with a 5′ upstream region in a wound-induced win2 gene from potato. Potential sites of transcriptional regulation in these genes are discussed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 90
    ISSN: 1615-6102
    Keywords: Chloroplast development ; Cotton ; Fluorescence induction kinetics ; Ultrastructure ; Immunocytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Many of the studies of chloroplast ontogeny in higher plants have utilized suboptimal conditions of light and growth to assess development. In this study, we utilized structural, immunological, and physiological techniques to examine the development of the chloroplast in fieldgrown cotton (Gossypium hirsutum cv. “MD 51 ne”). Our youngest leaf sample developmentally was completely folded upon itself and about 0.5 cm in length; leaves of this same plastochron were followed for three weeks to the fully expanded leaf. The chloroplasts at the earliest stage monitored had almost all of the lamellae in small, relatively electron-opaque grana, with relatively few thylakoids which were not appressed on at least one surface. During the development of the thylakoids, the membranes increase in complexity, with considerable stroma lamellae development and an increase in the number of thylakoids per granum. Besides the increase in complexity, both the size and numbers of the chloroplast increase during the development of the leaf. Developmental changes in six thylakoid proteins, five stromal proteins, and one peroxisomal protein were monitored by quantitative immunocytochemistry. Even at the earliest stages of development, the plastids are equipped with the proteins required to carry out both light and dark reactions of photosynthesis. Several of the proteins follow three phases of accumulation: a relatively high density at early stages, a linear increase to keep step with chloroplast growth, and a final accumulation in the mature chloroplast. Photosystem-II(PS II)-related proteins are present at their highest densities early in development, with an accumulation of other parts of the photosynthetic apparatus at a latter stage. The early accumulation of PS-II-related proteins correlates with the much lower ratio of chlorophylla tob in the younger leaves and with the changes in fluorescence transients. These data indicate that some of the conclusions on chloroplast development based upon studies of intercalary meristems of monocots or the greening of etiolated plants may not be adequate to explain development of chloroplasts in leaves from apical meristems grown under natural conditions.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 91
    ISSN: 1615-6102
    Keywords: Lupinus albus ; Nitrogen fixation ; Oxygen diffusion ; Glycoprotein ; Immunocytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The monoclonal antibodies MAC236 and MAC265, raised against a soluble component of pea nodules, were used to elucidate the presence and subcellular localization of glycoprotein epitopes during the development of lupin (Lupinus albus L. cv. Multolupa) nodules, by means of immunocytochemistry and Western blot analysis. These antibodies recognize a single band of 95 kDa in pea, soybean and bean nodules, whilst two different bands of 240 and 135 kDa cross-react with MAC236 and MAC265 respectively in lupin nodules. This fact may indicate that the recognized epitopes can be present in different subcellular compartments and/or play different roles through the development of functional nodules. The results show that MAC265 is mainly associated with Bradyrhizobium infection and with the development of nodule primordium, in the first stages of nodulation. MAC265 is also detected when glycoprotein transport takes place across the cytoplasm and the cell wall, and also in the intercellular spaces of the middle cortex, attached to cell walls. The amount of MAC265 remains constant through nodule development. In contrast the amount of MAC236 increases with nodule age, parallel to the establishment of nitrogenase activity. This antibody is localized in cytoplasmic globules attached to the inner side of cell walls in the middle cortex, and mainly in the matrix filling the intercellular spaces of the middle and inner cortex. This main site of localization of MAC236 may indicate a role in the functioning of the oxygen diffusion barrier.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 92
    ISSN: 1615-6102
    Keywords: Antiauxins ; Auxin ; Donorplant ; Nicotiana tabacum ; Pollen culture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Anthers ofNicotiana tabacum var. Badischer Burley contain endogenous auxins, one of these was identified as indoleacetic acid. At the developmental stage shortly after the first pollen mitosis the anthers contain equivalents of 0.1 mg IAA per kg fresh weight. This endogenous auxin level is maintained during the eight-day preculture of the anthers prior to isolated pollen culture. However, in anthers of “short-day” plants, which are characterized by a high proportion of embryogenic pollen at the end of preculture (Heberle-Bors andReinert 1979), an increase of the auxin level till the fourth day of culture is detectable. Preculture of anthers in the presence of an inhibitor of auxin synthesis (7-azaindole) and an antiauxin (α-(o-chlorophenoxy)-isobutyric acid) results in enhanced plantlet yield by pollen cultures. The significance of these observations for androgenesis is discussed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 93
    ISSN: 1615-6102
    Keywords: Flax ; Cell wall ; Golgi apparatus ; β-Galactans ; Immunocytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Most cell wall components are carbohydrate including the major matrix polysaccharides, pectins and hemicelluloses, and the arabinogalactan-protein proteoglycans. Both types of molecules are assembled in the Golgi apparatus and transported in secretory vesicles to the cell surface. We have employed antibodies specific to β-(1→6) and β-(1→4)-D-galactans, present in plant cell wall polysaccharides, in conjunction with immunofluorescence and electron microscopy to determine the location of the galactan-containing components in the cell wall and Golgi stacks of flax root tip tissues. Immunofluorescence data show that β-(1→4)-D-galactan epitopes are restricted to peripheral cells of the root cap. These epitopes are not expressed in meristematic and columella cells. In contrast, β-(1→6)-D-galactan epitopes are found in all cell types of flax roots. Immunogold labeling experiments show that both epitopes are specifically located within the wall immediately adjacent to the plasma membrane. They are also detected in Golgi cisternae and secretory vesicles, which indicates the involvement of the Golgi apparatus in their synthesis and transport. These findings demonstrate that the synthesis and localization of β-(1→4)-D-galactan epitopes are highly regulated in developing flax roots and that different β-linked D-galactans associated with cell wall polysaccharides are expressed in a cell type-specific manner.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 94
    ISSN: 1615-6102
    Keywords: Ferritin ; Nitrogen fixation ; Nodule development ; Plastid ; Legume ; Immunocytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary In eukaryotic organisms ferritin is a protein involved in the storage of iron. The occurrence of ferritin and its relationship to the effectiveness of the nitrogen-fixing activity have been previously studied during the early stages of the nodule development by biochemical methods. We have used immunocytochemistry techniques to determine the precise location of ferritin and the behavior of this protein along the nodule development. The major localization was found in plastids and amyloplasts of infected and uninfected cells of the three legume nodules studied. A decrease of the immunolabelling was observed in infected cells of lupin and soybean senescing nodules and in the senescent zone of indeterminate alfalfa nodules. In the cortex of soybean and lupin nodules, ferritin increased during nodule ageing and the immunogold particles were mainly located in crystalline structures. The putative role of ferritin and plastids during nodule development is discussed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 95
    Electronic Resource
    Electronic Resource
    Springer
    Protoplasma 204 (1998), S. 22-33 
    ISSN: 1615-6102
    Keywords: Actin ; Auxin ; Cell elongation ; Gravitropism ; Microfilaments ; Oryza sativa
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The rice mutantYin-Yang has been selected during a screen for resistance to cytoskeletal drugs and is characterized by alterations in epidermal cell length and a precocious onset of gravitropism. The elongation response of coleoptile segments to auxin does not reveal changes of auxin sensitivity inYin-Yang. However, in contrast to the wild type, cell elongation inYin-Yang is highly sensitive to the actin-polymerisation blocker cytochalasin D. This increased sensitivity to cytochalasin D requires optimal concentrations of auxin to become manifest. The auxin response of actin microfilaments in epidermal cells differs between wild type and mutant. In the wild type, the longitudinal microfilament bundles become loosened in response to auxin. In the mutant, these bundles disintegrate partially and are replaced by a network of short filaments surrounding the nucleus. Several aspects of the mutant phenotype can be mimicked in the wild type by treatment with cytochalasin D. The mutant phenotype is discussed in terms of signal-dependent changes of actin dynamics and the putative role of actin during cell elongation.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 96
    Electronic Resource
    Electronic Resource
    Springer
    Plant and soil 57 (1980), S. 31-39 
    ISSN: 1573-5036
    Keywords: Auxin ; Glycine max(L.) Merr. ; N fixation ; N-serve ; Soil N
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Plant dry weight, total N, and total Ca was increased at 0.1 and 1 ppm N-serve. At greater 10 ppm the plants showed visual symptoms of a stunted growth, stem elongation, flowers, and pods failed to form or were aborted, young leaves were curled, and roots were club shaped with many branches. These symptoms were increasingly evident with increasing N-serve application rates. The reason was attributed to an auxin effect. Dry wt and total N in the plant was less than the control at the higher N-serve applications. There was little effect on nitrogenase activity at less than 10 ppm N-serve. Nodulation tended to increase at 0.1 and 1 ppm N-serve. Nitrification was inhibited up to 104 days at 20 ppm N-serve. The soil pH of the high N-serve rates was decreased at 104 days probably due to nitrification. Generally there were little detectable differences among treatments in soil organic N. The average soil organic N from 0 to 104 days decreased by 0.01%. Average increase in total N within each pot at harvest was equivalent to about 138 kg N/ha.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 97
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 186 (1978), S. 551-558 
    ISSN: 1432-0878
    Keywords: C-cells ; Thyroid gland ; Immunocytochemistry ; Calcitonin antibody ; Mammals
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In the thyroid glands of the horse, pig, deer, mole, and rat, C-cells could be demonstrated by means of the immunocytochemical PAP-technique using rabbit antisera against human calcitonin. Only in ruminants, the crossreaction between the intracellularly stored antigen and the antibodies used appeared to be incomplete.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 98
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 177 (1977), S. 317-323 
    ISSN: 1432-0878
    Keywords: Hypothalamus ; Lamprey ; Vasotocinergic system ; Adenohypophysis ; Immunocytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary With the use of the unlabeled antibody peroxidase-antiperoxidase (PAP) technique at the light microscopic level, it was shown that the preoptico-hypophysial neurosecretory system of the adult migrating Lampetra fluviatilis is a vasotocinergic system. It does not synthesize vasopressin. The results are entirely consistent with earlier chromatographic and pharmacological indications that it produces little or no oxytocin-like peptide hormone. In the adenohypophysis, immunoreactive neurohypophysial peptidergic fibres are absent.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 99
    ISSN: 1432-0878
    Keywords: Pars intermedia of hypophysis ; Rana temporaria ; Mesotocinergic and vasotocinergic fibres ; Immunocytochemistry ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary With the use of the unlabeled antibody peroxidase-antiperoxidase (PAP) method at the electron microscopic level, it has been shown that the pars intermedia of the hypophysis of Rana temporaria contains a diffuse intercellular network of separate mesotocinergic and vasotocinergic nerve fibres.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 100
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 179 (1977), S. 211-224 
    ISSN: 1432-0878
    Keywords: Somatostatin (rat) ; Hypothalamus ; Fibers and perikarya ; Immunocytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Using the immunoenzyme bridge-technique at the light and electron microscopic levels, somatostatin can be demonstrated in the perikarya of the anterior periventricular nucleus, in the median eminence and in the parvocellular hypothalamic nuclei of the rat. In the latter regions the perikarya are negative, whereas a positive reaction for somatostatin is found in a delicate network of fibers and middle-sized granules of very small axons. In light of these results, the double function of somatostatin — as release inhibiting hormone and as transmitter — is discussed. The positive staining reaction in the organum vasculosum laminae terminalis of male and female rats as well as in the subfornical organ, the nucleus dorsalis thalami and the nucleus medialis habenulae in female controls and pregnant rats is not due to somatostatin-containing structures, but partly to substance P and partly to a substance which could not be defined.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...