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  • Immunocytochemistry  (52)
  • Zea mays  (43)
  • Springer  (94)
  • American Geophysical Union
  • American Meteorological Society
  • Oxford University Press
  • 1995-1999
  • 1990-1994  (94)
  • 1992  (94)
Collection
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  • Springer  (94)
  • American Geophysical Union
  • American Meteorological Society
  • Oxford University Press
  • Wiley-Blackwell  (6)
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  • 1995-1999
  • 1990-1994  (94)
Year
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Mycopathologia 117 (1992), S. 157-161 
    ISSN: 1573-0832
    Keywords: Phyllachora maydis ; Monographella maydis ; Coniothyrium phyllachorae ; Zea mays ; tarspot complex
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The tarspot complex is caused by the interaction of Phyllachora maydis and Monographella maydis. Coniothyrium phyllachorae, possibly a mycoparasite, is found in older ascostromata of P. maydis, which always appears first causing tarspot. M. maydis follows and is responsible for the damaging “fisheye” symptom. The fisheye symptom is always associated with a tarspot in the center of the lesion, whereas 12 to 20% of the Phyllachora ascostromata remained free of M. maydis. Inoculations of maize leaves with the Microdochium anamorph of the Monographella (usually produced in lesions) failed to produce infections. Some infections with M. maydis were, however, obtained under unusual conditions in the field. Inoculations onto tarspots in the laboratory were unsuccessful, but in field experiments inoculations with conidia of M. maydis enhanced severity of the tarspot complex. Fisheye symptoms of the complex naturally appear 2 to 7 days after the manifestation of P. maydis. This is followed a week later by the appearance of M. maydis which became predominant in the lesions and is associated with empty perithecia of P. maydis. In the early stages of the tarspots pycnidia of the anamorph of P. maydis, Linochora sp., could occasionally be observed. Ascomata of M. maydis were rare in the field. Of the 36 genetic materials of CIMMYT tested, 30 developed the fisheye symptom, 4 tarspots only and 2 remained free of symptoms
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  • 2
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    Mycopathologia 119 (1992), S. 181-190 
    ISSN: 1573-0832
    Keywords: aflatoxin B1 ; electron microscopy ; in vitro ; immature maize embryo ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Immature maize (Zea mays L.) embryos were treated with aflatoxin B1 concentrations, ranging from 0.1 μg ml−1 to 25 μg ml−1. Below 5 μg ml−1 aflatoxin B1, root and shoot elongation was not significantly inhibited. Ultrastructurally, root tip cells showed little deterioration, except a possible diffused clearing in mitochondria and plastids. As the toxin concentration was increased above 5 μgml−1, shoot, and particularly root elongation, was progressively inhibited. Associated with this, there was an apparent decrease in the ribosome population. Furthermore, membranes, particularly the vacuolar membrane, became abnormal and vacuolar distension occurred. At 20 and 25 μg ml−1, these effects were exacerbated, and mitochondria and plastid structure was disrupted. At these concentrations, there was evidence of a disruption in lipid metabolism. The results are discussed in the context of known aflatoxin effects on cellular control mechanisms and ultrastructure in animal systems.
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  • 3
    ISSN: 1432-041X
    Keywords: Sea urchin ; Jelly coat ; Accessory cell ; Oogenesis ; Immunocytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The immunocytochemical localization of the egg-jelly macromolecule, a fucose sulphate glycoconjugate (FSG) that induces the acrosome reaction in spermatozoa, was investigated in ovaries of the sea urchin Hemicentrotus pulcherrimus by use of a polyclonal antibody. The polyclonal antibody reacted with the accessory cells and oocytes in the ovarian lumen. In the accessory cells, evidence of an intense immunohistochemical reaction was observed in many globules of variable density. Products of the specific immunohistochemical reaction were frequently observed in the surface region of oocytes, at a distance from the ovarian wall. At the ultrastructural level, the polyclonal antibody was found to react with the material present in the vacuole-like structures of the globules in the accessory cells. Many gold particles, demonstrating specific immunolabelling, were associated with well-developed microvilli on the vitellogenic oocytes. In the mature oocytes, intense labelling was observed in the jelly coat but not in the vitelline coat. By contrast, oogonia and early oocytes were barely labelled. Quantitative data indicated that the extent of immunolabellings in the surface region of oocytes was very high in the vitellogenic and mature oocytes. In all cases, neither the oocyte cytoplasm nor the subcellular organelles were labelled. These results suggest that FSG is produced by the accessory cells and is deposited initially on the surface of vitellogenic oocytes for the formation of jelly. These findings may provide a new insight into the role of the accessory cells in the reproductive process of the sea urchin.
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  • 4
    ISSN: 1432-0827
    Keywords: Growth hormone ; Growth hormone receptor ; Odontogenesis ; Bone remodeling ; Immunocytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Growth hormone (GH) may regulate tooth formation and bone remodeling associated with tooth eruption. This study reports the distribution of growth hormone receptor/binding protein in developing rat molars and adjacent alveolar bone by immunocytochemistry using well-characterized anti-growth hormone receptor monoclonal antibodies. These tissues represent an excellent model for studying the ontogenic changes that occur in odontogenic and osteogenic cells, as these cells are found in linear arrays displaying the various stages of morphological and functional differention, and differentiated function. Immunoreactivity was first seen in precementoblasts in contact with the epithelial root sheath, and preodontoblasts. However, growth hormone receptor immunoreactivity was associated primarily with the cytoplasm of odontogenic and osteogenic cells forming their respective matrices. Thus, cementoblasts and odontoblasts at sites of new matrix formation showed intense immunoreactivity whereas cementocytes and mature odontoblasts at later stages of tooth development were nonreactive. Osteoblasts engaged in intramembranous ossification in the alveolar bone were positive, although osteocytes and endosteal cells were immunonegative. Osteoclasts at sites of alveolar bone remodeling resorption were also immunopositive. These patterns of receptor expression parallel the ontogenic sequences of odontogenic and osteogenic cells and suggest that GH promotes the functional state of these cells. Our results also imply that GH may influence differentiation or differentiated functions associated with odontogenesis, osteogenesis, and bone remodeling independent of systemic insulin-like GF-I.
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  • 5
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    Plant cell reports 11 (1992), S. 567-570 
    ISSN: 1432-203X
    Keywords: Microspore ; Electroporation ; Transformation ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The ability to deliver and detect reporter gene activity in maize microspores was tested. Tested expression vectors contained the chloramphenicol acetyl transferase (CAT) gene and one of the following promoter-intron combinations: 1) cauliflower mosaic virus (CaMV 35S), 2) CaMV 35S + maize alcohol dehydrogenase 1 intron 6 (Adh1-I6), 3) maize alcohol dehydrogenase 1 + intron 1 (Adh1-I1), or 4) maize ubiquitin 1 + intron 1 (Ubiq 1-I1) promoter + intron. The expression vectors were delivered into maize microspores using electroporation or polyethylene glycol (PEG). Both methods were effective for delivering free DNA into microspores. Although all four promoters were active in maize protoplasts, only two promoters were active in maize microspores. The CaMV 35S and the Adh1 promoters did not promote gene expression in maize microspore. The CaMV 35S + Adh1-I6 and Ubiq1-I1 promoters produced high levels of CAT activity in maize microspores.
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  • 6
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    Sexual plant reproduction 5 (1992), S. 89-100 
    ISSN: 1432-2145
    Keywords: Actin ; Cytoskeleton ; Generative cell ; Immunocytochemistry ; Microtubule ; Mitosis ; Phragmoplast ; Pollen ; Rhodamine phalloidin ; Sperm
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Disagreement has arisen over the presence of actin-containing microfilaments (Mfs) in angiosperm generative cells and sperm (GSP). In order to address this issue, we subjected GSP of Tradescantia virginiana, Nicotiana tabacum and Rhododendron laetum to a series of localizations using different antiactins, rhodamine phalloidin and antimyosin. Coordinate staining with antitubulin and Hoechst 33258 defined the status of the microtubule (Mt) cytoskeleton and stages of generative cell division. Additional experiments utilized cytochalasin D (CD). In no instance could Mfs be detected in GSP of the three species. Instead, Mfs seen at the periphery of GSP appear to be continuous with vegetative Mfs and thus are in the vegetative cytoplasm. Mfs are not seen in the constriction zone of dividing T. virginiana generative cells, nor are they indicated in the phragmoplast of N. tabacum and R. laetum. Myosin localizations reveal punctate staining in the vegetative cytoplasm and a thin line of fluorescence around the the outside of the generative cell. While CD seems to delay generative cell division, cytokinesis still takes place. CD-induced Mf fragments are evident in the vegetative cytoplasm but not in GSP. The weight of evidence therefore indicates that GSP do not contain Mfs. The implications of this conclusion for the behavior of GSP and the mechanism of cytokinesis in dividing generative cells are considerable.
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  • 7
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    Sexual plant reproduction 5 (1992), S. 224-226 
    ISSN: 1432-2145
    Keywords: Zea mays ; Maize ; Polyembryony
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Two types of cleavage polyembryony are described in the inbred line VIR 17 of maize. Suspensorial embryony was observed to occur spontaneously. Typical cleavage of the zygotic proembryo occurred spontaneously, but could also be induced by treating the developing caryopses with 2,4-Dichlorophenoxyacetic acid (2,4-D) on the second day after pollination. 2,4-D was active as a decorelative factor also evoking the expression of totipotency in individual proembryonal cells.
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  • 8
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    Sexual plant reproduction 5 (1992), S. 227-231 
    ISSN: 1432-2145
    Keywords: Zea mays ; Maize ; Pollen-tube growth regulation ; In vitro pollination
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary In vitro pollen-tube growth in maize was studied using an in vitro pollination system. In the ‘cut-silk’ method, ovaries with silks were placed on medium in vitro, whereafter the silk was cut and the upper part of the silk was pollinated. Pollen tubes were not able to bridge the space between the two silk parts. Even when silk parts were tightly connected, pollen tubes still were not able to pass the cut ends and reach the lower silk part. Pollen-tube growth rates and the direction of tube growth were not influenced by the presence or absence of an ovary. Prepollination did not have any influence on pollen-tube growth rate. Measurements of pollen-tube growth rate also showed that there was no ‘population effect’, i.e. growth rate was not stimulated by pollination with an excess of pollen grains. We found that the direction in which maize pollen grew was determined only by the positioning of the silk hairs.
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  • 9
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    Plant cell reports 11 (1992), S. 535-539 
    ISSN: 1432-203X
    Keywords: Zea mays ; in vitro culture ; in vitro pollen ; pollen germination ; fertilization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Maturation of maize pollen was obtained in male reproductive structures cultured in vitro. Immature tassels containing microspores at the mid-uninucleate to late-binucleate stage of development were excised and spikelets, anthers, and/or isolated microspores were cultured on a medium capable of supporting pollen maturation. Microspore mitosis, culminating in the production of starch-filled, trinucleate pollen capable of germination, was observed after 7–15 days, depending on the genotype and stage at which the cultures were initiated. Up to 100%, 70%, and 20% of the cultured spikelets, anthers, and isolated microspores, respectively, produced mature pollen, which germinated, however, at different frequencies (i.e., spikelets, 50–70%; anthers, 5–10%; microspores, 〈1%). Mature kernels were produced following fertilization with pollen from cultured spikelets and anthers. These procedures provide methods for the in vitro manipulation of a significant phase of the maize life cycle.
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  • 10
    ISSN: 1432-203X
    Keywords: Zea mays ; Matrix-associated ; DNA ; repetitive sequences ; DNA loops
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In order to elucidate some features of the topological organization of DNA within the plant nucleus, DNA fragments involved in the attachment of the DNA loops to the nuclear matrix in maize were studied. The matrix-associated DNA from dry embryo and meristematic cells after extensive digestion with DNase I and high salt treatment was about 2% of the total DNA, sized within the range of 50 and 250 bp. This DNA was found to be enriched in repetitive DNA sequences, both for nuclei from dry embryo and meristematic cells. The loop size of the DNA in cells of Zea mays appeared to be between 5 and 25 kbp.
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  • 11
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    Biology and fertility of soils 13 (1992), S. 142-146 
    ISSN: 1432-0789
    Keywords: A value ; Common bean ; N remobilization ; Soil N balance ; Atom% 15N excess ; Phaseolus vulgaris ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The common bean (Phaseolus vulgaris L.) is generally regarded as a poor N2 fixer. This study assessed the sources of N (fertilizer, soil, and fixed N), N partitioning and mobilization, and soil N balance under field conditions in an indeterminate-type climbing bean (P. vulgaris L. cv. Cipro) at the vegetative, early pod-filling, and physiological maturity stages, using the A-value approach. This involved the application of 10 and 100 kg N ha-1 of 15N-labelled ammonium sulphate to the climbing bean and a reference crop, maize (Zea mays L.). At the late pod-filling stage (75 days after planting) the climbing bean had accumulated 119 kg N ha-1, 84% being derived from fixation, 16% from soil, and only 0.2% from the 15N fertilizer. N2 fixation was generally high at all stages of plant growth, but the maximum fixation (74% of the total N2 fixed) occurred during the interval between early (55 days after planting) and late podfilling. The N2 fixed between 55 and 75 days after planting bas a major source (88%) of the N demand of the developing pod, and only about 11% was contributed from the soil. There was essentially no mobilization of N from the shoots or roots for pod development. The cultivation of common bean cultivars that maintain a high N2-fixing capacity especially during pod filling, satisfying almost all the N needs of the developing pod and thus requiring little or no mobilization of N from the shoots for pod development, may lead to a net positive soil N balance.
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  • 12
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    Archives of microbiology 157 (1992), S. 218-222 
    ISSN: 1432-072X
    Keywords: Denitrification ; N2O reductase ; Nitrite reductase ; Immunocytochemistry ; Localization ; Two-dimensional electrophoresis ; Cell fractionation ; Pseudomonas stutzeri
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Immunogold labelling techniques on ultrathin sections of low temperature embedded cells yielded evidence for the periplasmic location of the respiratory enzymes N2O reductase and nitrite reductase (cytochrome cd 1) in Pseudomonas stutzeri strain ZoBell. Cell fractionation by spheroplast preparation and two-dimensional electrophoresis showed the absence of a membrane association of these enzymes. Immunocytochemical localization of N2O reductase in a mutant strain deficient in the chromophore of N2O reductase showed the gold label at the cell periphery, indicating that the copper chromophore processing takes place after export of this protein's apoform.
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  • 13
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    Journal of chemical ecology 18 (1992), S. 1227-1237 
    ISSN: 1573-1561
    Keywords: Western corn rootworm ; Diabrotica virgifera virgifera ; Coleoptera ; Chrysomelidae ; bacteria ; carbon dioxide ; pheromone ; semiochemicals ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract FemaleDiabrotica virgifera virgifera LeConte were allowed to choose between oviposition substrates that were and those that were not associated with potential sources of semiochemicals. Females deposited over five times more eggs on moist towelettes that were treated with homogenates of female abdomens than on towelettes treated with distilled water. Similar results were obtained when screening separated the homogenates from the towelettes, indicating that odors alone could elicit the response. In contrast, females did not choose towelettes that had previously been used for oviposition or towelettes containing eggs over unused towelettes. Further tests with homogenates of abdomens and a bacteriostatic agent (sorbate) indicated that the females were probably responding to bacterial odors rather than an oviposition-enhancing pheromone. Four strains of bacteria were isolated from a homogenate of female abdomens; females deposited 4 to 16 times more eggs on substrates with odors of the bacteria than on substrates with odors of uninoculated nutrient agar. In no-choice tests, bacterial odors did not increase the number of eggs deposited per female beetle; however, in choice tests with dishes that tended to retain any beetles that entered, there were more eggs per female (but not more beetles) after 24 hr in dishes with bacterial odors than in those without the odors. Females also chose dishes with odors of excised maize (Zea mays L.) roots or elevated levels of carbon dioxide over “control” dishes.
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  • 14
    ISSN: 1573-5028
    Keywords: geminivirus ; agroinfection ; Zea mays ; large intergenic region (LIR)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Maize streak virus as well as other geminiviruses contain a potential hairpin structure with the conserved sequence TAATATTAC in the loop. We assessed the possible involvement of this structure in replication and symptom induction of the virus. A series of insertion and deletion mutants were analyzed by agroinfection. Deletion of the hairpin or insertions in the conserved sequence abolished symptom development. Viral DNA could not be detected in the infected tissue. However, a mutant with a point mutation in the ‘conserved’ sequence, isolated after inoculation of maize plants with an insertion mutant, was able to replicate and to induce symptoms.
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  • 15
    ISSN: 1573-5028
    Keywords: cortex ; developmental regulation ; in situ hybridization ; organ-specific gene expression ; roots ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A near full-length cDNA clone (pZRP3) corresponding to an mRNA that accumulates specifically in roots of maize was isolated. The ZRP3 mRNA is ca. 600 nucleotides in length. The amino acid sequence of the predicted polypeptide is rich in leucine (16%), proline (11%), and cysteine (8.5%). The zrp3 gene appears to be expressed exclusively in roots, whereas other ZRP3-related genes are expressed in additional organs of the maize plant. In situ hybridization shows that ZRP3 mRNA accumulation is largely confined to the cells of the cortical ground meristem. Furthermore, accumulation of this mRNA occurs within a distinct subset of cortical cells, the inner three to four cell layers.
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  • 16
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    Plant molecular biology 20 (1992), S. 1159-1168 
    ISSN: 1573-5028
    Keywords: DNA polymerase ; germination ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Three different DNA polymerase activities can be resolved by passing a protein extract from 24 h imbibed maize axes through DEAE-cellulose. These activities have been numbered 1, 2 and 3, according to their elution order. One of them, DNA polymerase 2, elutes at 100–120 mM phosphates. This enzyme was further purified by passing it through Heparin-Sepharose, Sephacryl S-300 and DNA cellulose. Purification was nearly 5000-fold. The enzyme needs Mg2+, is stimulated by K+, has an optimum pH of 7.0 and its optimum temperature is 30–37 °C. Specific inhibitors for different types of polymerases, such as aphidicolin, dideoxythymidine triphosphate and N-ethyl maleimide, gave intermediate values of inhibition, making impossible the definition of the type of enzyme purified by its inhibitory pattern. SDS-PAGE indicated the presence of several bands of molecular masses of 28–40, 56 and 15 kDa. Most of these bands could be visualized when proteins from crude extracts were analyzed by western blot, using an antibody against calf thymus DNA polymerase α. A high molecular mass (around 500 kDa) was calculated by western blot of native gels using the same antibody. Finally, specific activity of this enzyme increased 100-fold during maize germination whereas polymerase 3 virtually did not increase. Furthermore, immunoprecipitation experiments with the antipolymerase α-antibody showed a decrease in DNA polymerase activity by 70%. The possibility that polymerase 2 is a replicative enzyme is discussed.
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  • 17
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    Plant molecular biology 18 (1992), S. 847-849 
    ISSN: 1573-5028
    Keywords: cDNA ; nucleotide sequence ; glycine-rich proteins ; chemical stress ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
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  • 18
    ISSN: 1573-5028
    Keywords: promoter ; electroporation ; protoplasts ; transient assay ; Agrobacterium ; Ti plasmid ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Regulatory elements controlling transcriptional activity of the mannopine synthase 2′ promoter (mas 2′) were defined by analysis of deletion mutants in transient expression assays in maize protoplasts. Deletion of the region between −305 and −290 containing sequence similarity to the octopine synthase (ocs) promoter element reduced activity by 67% compared to wild type activity. Less than 1% of the activity remained in 5′ deletions downstream of −153. Inclusion of various heterologous enhancer-like sequences immediately upstream of position −325 increased activity by up to 7.5-fold. Insertion of the −325 to −275 sequence alone, or in combination with heterologous enhancer-like elements, restored activity of some of the 5′-deletion mutants. Restoration of activity was not obtained with mutants deleted past position −127. Our results suggest that a single class of nuclear proteins from maize interact with high affinity at elements designated mas b (−306 to −275; mas 1′ element), d (−127 to −108), and e (−82 to −39; mas 2′ element) as well as the 20 bp element from the ocs promoter. Although the binding site at mas d only appears to accommodate a single protein, this element has the potential to make a weak, but positive, contribution to the activity of the mas 2′ promoter. The binding of nuclear proteins could not be demonstrated at mas a and c, both of which showed limited homology to the ocs element. Mutational evidence suggested that mas a and c may also contribute to mas 2′ transcription.
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  • 19
    ISSN: 1573-5028
    Keywords: ribosomal protein ; rps12 ; rpl20 ; clpP ; chloroplast genome ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
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  • 20
    ISSN: 1573-5028
    Keywords: cycloheximide ; leaf ; nitrate induction ; nitrate reductase transcript ; root ; scutellum ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The nitrate induction of NADH:nitrate reductase mRNA in maize roots, scutella and leaves was investigated in the presence and absence of inhibitors of protein synthesis. In the absence of inhibitors, nitrate treatment caused a fairly rapid (2 to 3 h) increase in the level of the nitrate reductase transcript in all tissues. When cytoplasmic protein synthesis was inhibited by cycloheximide, nitrate reductase mRNA was induced by nitrate in all tissues to levels equal to or greater than those found with nitrate treatment alone. Treatment of maize tissues with cycloheximide in the absence of nitrate had only a small effect on the accumulation of the nitrate reductase mRNA. Inhibition of organellar protein synthesis with chloramphenicol also had little or no effect on nitrate-induced nitrate reductase mRNA accumuiation in roots and scutella, but did appear to partially inhibit appearance of transcript in leaves. Excision of scutella in the absence of nitrate was sufficient to cause some accumulation of the nitrate reductase transcript. Since cytoplasmic protein synthesis was not required for expression of nitrate reductase transcripts, induction of these transcripts by nitrate is a primary response of maize to this environmental signal. Thus, it appears that the signal transduction system mediating this response is constitutively expressed in roots, scutella and leaves of maize.
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  • 21
    ISSN: 1573-5028
    Keywords: Arabidopsis thaliana ; ATPase ; cpn60 ; developmental regulation ; molecular chaperones ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Mitochondria contain a nuclear-encoded heat shock protein, HSP60, which functions as a chaperonin in the post-translational assembly of multimeric proteins encoded by both nuclear and mitochondrial genes. We have isolated and sequenced full-length complementary DNAs coding for this mitochondrial chaperonin in Arabidopsis thaliana and Zea mays. Southern-blot analysis indicates the presence of a single hsp60 gene in the genome of A. thaliana. There is a high degree of homology at the predicted amino acid levels (43 to 60%) between plant HSP60s and their homologues in prokaryotes and other eukaryotes which indicates that these proteins must have similar evolutionarily conserved functions in all organisms. Northern- and western-blot analyses indicate that the expression of the hsp60 gene is developmentally regulated during seed germination. It is also heat-inducible. Developmental regulation of the (β-subunit) of F1-ATPase, an enzyme complex that is involved in the cyanide-sensitive mitochondrial electron transport system, indicates that imbibed embryos undergo rapid mitochondrial biogenesis through the early stages of germination. Based on the functional role of HSP60 in macromolecular assembly, these data collectively suggest that the presence of higher levels of HSP60 is necessary during active mitochondrial biogenesis, when the need for this protein is greatest in assisting the rapid assembly of the oligomeric protein structures.
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  • 22
    ISSN: 1573-5028
    Keywords: pollen-specific gene expression ; promoter analysis ; transient assays ; Tradescantia ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We have previously reported the isolation and characterization of a gene (Zm 13) from Zea mays which shows a pollen-specific pattern of expression. Stably transformed tobacco plants containing a reporter gene linked to portions of the Zm 13 5′ flanking region show correct temporal and spatial expression of the gene. Here we present a more detailed analysis of the 5′ regions responsible for expression in pollen by utilizing a transient expression system. Constructs containing the β-glucuronidase (GUS) gene under the control of various sized fragments of the Zm13 5′ flanking region were introduced into Tradescantia and Zea mays pollen via high-velocity microprojectile bombardment, and monitored both visually and with a fluorescence assay. The results suggest that sequences necessary for expression in pollen are present in a region from −100 to −54, while other sequences which amplify that expression reside between −260 and −100. The replacement of the normal terminator with a portion of the Zm13 3′ region containing the putative polyadenylation signal and site also increased GUS expression. While the −260 to −100 region contains sequences similar to other protein-binding domains reported for plants, the −100 to −54 region appears to contain no significant homology to other known promoter fragments which direct pollen-specific expression. The microprojectile bombardment of Tradescantia pollen appears to be a good test system for assaying maize and possibly other monocot promoter constructs for pollen expression.
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  • 23
    ISSN: 1432-1890
    Keywords: Ericaceae ; Mycorrhizal fungi ; Acid phosphatase ; Protein expression ; Immunocytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The activity of acid phosphatase produced in pure culture by the endomycorrhizal fungus Hymenoscyphus ericae (Read) Korf & Kernan (H. ericae LPA 2) was inhibited by high phosphorus levels, alkaline pH, fluoride, molybdate and mannosidase, and activated by concanavalin A. Over 80% of the enzyme activity was due to two wall-bound acid phosphatase isozymes with the characteristics of mannose-rich glycoproteins. Antiserum was raised against the major, low-molecular-weight wall isozyme and its activity tested by immunoblotting and ELISA. The antiserum cross reacted 100% with exocellular (excreted) and 28% with cytoplasmic cellular fractions of H. ericae (LPA 2) cultures, and showed high reactivity with other strains of H. ericae but not with fungal isolates from Erica hispidula L. or E. mauritanica L. Ultrastructural localization of acid phosphatase by cytoenzymology and indirect immunogold labelling confirmed its association with the fungal wall in pure culture and showed that the influence of a high phosphorus level, fluoride and molybdate is through inactivation of the enzyme. Intense acid phosphatase activity, sensitive to the latter inhibitors, was also present on external hyphae growing over a host or non-host root but it was weak or absent from intracellular hyphae where these developed within a host root. Indirect immunolabelling confirmed that this acid phosphatase was of fungal origin and that the specific inhibitory effect of host cells is due to inactivation of the enzyme rather than repression of its synthesis. Possible implications of fungal acid phosphatase in ericoid endomycorrhizal infection processes are discussed together with mechanisms that may be regulating the enzyme activity.
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  • 24
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    Theoretical and applied genetics 84 (1992), S. 798-802 
    ISSN: 1432-2242
    Keywords: Zea mays ; C-banding ; Cell size ; Chloroplast number ; Cold tolerance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary C-band number, guard cell length, and chloroplast number per guard cell were determined for eight maize populations. These populations consisted of maize selected for cold tolerance at the University of Nebraska as well as the original unselected populations. The genome size of these populations had previously been determined. C-band number fluctuated concertedly with the changes in genome size indicating that deletions and additions of constitutive heterochromatin occurred during selection, resulting in altered genome sizes. Guard cell size of all the cold tolerant populations was greater than the cell size of the respective nonselected populations. Chloroplast number per guard cell was also higher in all the cold tolerant populations than in their parental populations, but the increases were not statistically significant. The results indicate that changes in genome size that occurred during selection for cold tolerance are the result of changes in amounts of C-band heterochromatin and that the selection process results in an increase in cell size in the cold tolerant populations.
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  • 25
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    Cell & tissue research 270 (1992), S. 395-404 
    ISSN: 1432-0878
    Keywords: Nucleus sacci vasculosi ; Ultrastructure ; Immunocytochemistry ; Hypothalamus ; Tuberculum posterius ; Scyliorhinus caniculus, Raja undulata (Elasmobranchii)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The elasmobranch nucleus sacci vasculosi was studied by means of electron microscopy (in the dogfish) and immunocytochemistry (in the dogfish and the skate) by using antibodies against tyrosine hydroxylase, alpha-melanocyte-stimulating hormone, somatostatin, serotonin, and substance P. Ultrastructural study of the dogfish nucleus sacci vasculosi shows the presence of medium-sized cells that possess numerous mitochondria but that have no dense-core vesicles in the cytoplasm or in cell processes. Fibres of the conspicuous tractus sacci vasculosi have a beaded appearance and form conventional synapses with dendrites and cell perikarya of the nucleus sacci vasculosi. The perikarya of this hypothalamic nucleus were not immunoreactive to any of the antibodies tested, and fibres immunopositive to tyrosine hydroxylase, alpha-melanocyte-stimulating hormone, somatostatin, serotonin, and substance P were scarce within this nucleus, in both the dogfish and the skate. Dorsal to the nucleus sacci vasculosi, there are numerous positive neuronal processes in addition to many small neurons that show immunoreactivity to alpha-melanocyte-stimulating hormone, somatostatin and tyrosine hydroxylase. Two types of neuron occur in this dorsal region, displaying dense-core vesicles of either 100–160 nm or 60–100 nm diameter in their cytoplasm; they were identified as peptide-containing and monoamine-containing neurons, respectively. The neuropil of this region has a significantly different ultrastructure from that of the nucleus sacci vasculosi, with many processes containing dense-core vesicles. This group of neurons, located dorsal to the nucleus sacci vasculosi and showing (a) immunoreactivity to neuropeptides or to monoamine-synthesizing enzyme, and (b) cytoplasm with dense-core vesicles, was considered not to be a part of the nucleus sacci vasculosi but rather part of the nucleus tuberculi posterioris. These results support the non-peptidergic and non-aminergic character of the nucleus sacci vasculosi.
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  • 26
    ISSN: 1432-0878
    Keywords: Serotonin ; Whole-mount ; Immunocytochemistry ; Insect ventral nervous system ; Interneurons ; Efferent neurons ; Leptinotarsa decemlineata (Insecta)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In an immunohistochemical study of the ventral nerve cord of L. decemlineata, five distinct neuron categories were distinguished: 1) Two paired segmental twin interneurons occur in each ganglion or neuromere; their axons distribute processes over almost the entire nerve cord and run to the cerebral ganglion complex. In contrast, other axons are distributed locally. 2) Four large frontal neurosecretory neurons occur in the suboesophageal ganglion (SOG), two of which have axons that run into the mandibular nerves to form a neurohemal plexus on the surface of cerebral nerves. 3) A pair of large caudal neurons occur in the terminal ganglion and innervate the hindgut. 4) Local miniature interneurons occur in the SOG. 5) Terminal neurons are present in the last abdominal ganglion. Segmental twin interneurons appear to be grouped into 3 ‘functional units’ spanning several ganglia. Their axons run to specific projection areas, which separate the functional units, and which mark the externally visible separation of condensed ganglion complexes. A possible role of the most caudal functional unit might be the synaptic control of caudal neurons innervating the hindgut.
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  • 27
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    Cell & tissue research 270 (1992), S. 469-474 
    ISSN: 1432-0878
    Keywords: Pericytes ; Angiogenesis ; Capillaries ; Capillary sprouting ; Desmin ; Immunocytochemistry ; Rat Adenocarcinoma cells, rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary To investigate the participation of microvascular pericytes in the process of capillary sprouting, we examined whole-mount preparations of the rat mesentery by use of a double immunofluorescence approach. Angiogenesis was induced by intraperitoneal injections of either the mast cell-degranulating substance compound 48/80 or tumor cell-conditioned medium. Capillary sprouts were visualized by staining with rhodaminconjugated phalloidin and pericytes were simultaneosly stained by an antibody to the intermediate filament protein desmin. Developing pericytes were negative for the smooth-muscle isoform of α-actin, bbut were clearly reactive for desmin. Pericytes appear to be involved in the carliest stages of capillary sprouting. Pericytes were regularly found lying at and in front of the advancing tips of endothelial sprouts. At many sites pericytes were seen to bridge the gap between the leading edges of opposing endothelial sprouts, which were apparently preparing to merge, suggesting that pericytic processes may serve as guiding structures aiding outgrowth of endothelial cells.
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  • 28
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    Cell & tissue research 267 (1992), S. 125-130 
    ISSN: 1432-0878
    Keywords: Sensory ganglia ; Sympathetic ganglia ; Parasympathetic ganglia ; Basic fibroblast growth factor ; Substance P ; Somatostatin ; Bombesin ; Immunocytochemistry ; Rat (Wistar: Han)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The distribution of basic fibroblast growth factor (bFGF)-immunoreactivity (IR) was studied in rat sensory and autonomic ganglia. In postnatal and adult sympathetic superior cervical ganglia and in adult parasympathetic otic ganglia no bFGF-staining was found. Postnatal and adult neural crest-and placode-derived sensory ganglia displayed intensive bFGF-IR in a neuronal subpopulation. This subpopulation was characterized by use of consecutive sections of adult dorsal root ganglia stained with antibodies against substance P, somatostatin, bombesin, and bFGF. Basic FGF was colocalized with the somatostatin/bombesin subpopulation but not with substance P.
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  • 29
    ISSN: 1432-0878
    Keywords: Dopamine ; Tyrosine hydroxylase ; Histamine ; Immunocytochemistry ; Insect nervous system ; Drosophila melanogaster, Phormia terraenovae, Calliphora erythrocephala (Insecta)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The distribution and morphology of neurons reacting with antisera against dopamine (DA), tyrosine hydroxylase (TH) and histamine (HA) were analyzed in the blowflies Calliphora erythrocephala and Phormia terraenovae. TH-immunoreactive (THIR) and HA-immunoreactive (HAIR) neurons were also mapped in the fruitfly Drosophila melanogaster. The antisera against DA and TH specifically labeled the same neurons in the blowflies. About 300 neurons displayed DA immunoreactivity (DAIR) and THIR in the brain and subesophageal ganglion of the blowflies. Most of these neurons were located in bilateral clusters; some were distributed as bilateral pairs, and two ventral unpaired median (VUM) neurons were seen in the subesophageal ganglion. Immunoreactive processes were found in all compartments of the mushroom bodies except the calyces, in all divisions of the central body complex, in the medulla, lobula and lobula plate of the optic lobe, and in non-glomerular neuropil of protocerebrum, tritocerebrum and the subesophageal ganglion. No DA or TH immunoreactivity was seen in the antennal lobes. In Drosophila, neurons homologous to the blowfly neurons were detected with the TH antiserum. In Phormia and Drosophila, 18 HA-immunoreactive neurons were located in the protocerebrum and 2 in the subesophageal ganglion. The HAIR neurons arborized extensively, but except for processes in the lobula, all HAIR processes were seen in non-glomerular neuropil. The deuto- and tritocerebrum was devoid of HAIR processes. Double labeling experiments demonstrated that TH and HA immunoreactivity was not colocalized in any neuron. In some regions there wasm however, substantial superposition between the two systems. The morphology of the extensively arborizing aminergic neurons described suggests that they have modulatory functions in the brain and subesophageal ganglion.
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  • 30
    ISSN: 1432-0878
    Keywords: Fetal intermediate lobe ; Tissue culture ; Immunocytochemistry ; In situ hybridization ; Dopamine ; Rat (Wistar)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Organotypic cultures, in defined medium, of pituitary primordia obtained from 15-day-old rat fetuses were performed in order to study the in vitro differentiation of melanotrophic cells. The morphological and ultrastructural features of the transplants resembled those of the gland developing in vivo. In situ hybridization on semi-thin sections, using a 35S-labelled oligonucleotide probe, revealed pro-opiomelanocortin-mRNA-containing cells on the first day of culture in the anterior lobe and after 2–3 days in the intermediate lobe. Immunoperoxidase labelling of adjacent sections showed that the same cells reacted with antibodies against α-melanocyte-stimulating hormone (αMSH), γ3 and adrenocorticotropic hormone in both lobes. The pro-opiomelanocortin-mRNA-containing cells formed progressively conspicuous areas in the intermediate lobe, which was almost uniformly labelled after 6 days. In the anterior lobe, these cells remained scattered in small cell groups, and colloidal gold immunolabelling showed the progressive disappearance of αMSH labelling from the secretory vesicles in cells exhibiting morphological features of adult corticotrophic cells. Both the αMSH content of the explants and αMSH release into the culture medium increased with time. Treatment with the dopamine agonist bromocriptine induced a strong dose-dependent decrease in αMSH secretion, which was significant after 3 days in culture, indicating that dopamine D2 receptors are able to regulate hormonal release of melanotrophic cells at early stages. This system constitutes a suitable model for further studies of factors controlling cell differentiation and cellular interactions involved in histogenesis.
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  • 31
    ISSN: 1432-0878
    Keywords: Cerebral ganglia ; Neurohormones ; Molluscan insulin-related peptide ; Immunocytochemistry ; Tannic acid ; Planorbarius corneus (Mollusca)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Two groups of cerebral dorsal cells of the pulmonate snail Planorbarius corneus stain positively with antisera raised against synthetic fragments of the B- and C-chain of the molluscan pro-insulin-related prohormone, proMIP-I, of another pulmonate snail, Lymnaea stagnalis. At the light-microscopic level the somata of the dorsal cells and their axons and neurohemal axon terminals in the periphery of the paired median lip nerves are immunoreactive with both antisera. Furthermore, the canopy cells in the lateral lobes of the cerebral ganglia are positive. In addition, MIPB-immunoreactive neurons are found in most other ganglia of the central nervous system. At the ultrastructural level, pale and dark secretory granules are found in somata and axon terminals of the dorsal cells. Dark granules are about 4 times as immunoreactive to both antisera as pale granules. Release of anti-MIPB- and anti-MIPC-immunopositive contents of the secretory granules by exocytosis is apparent in material treated according to the tannic acid method. It is concluded that the dorsal and canopy cells synthesize a molluscan insulin-related peptide that is packed in the cell body into secretory granules and that is subsequently transported to the neurohemal axon terminals and released into the hemolymph by exocytosis. Thus, MIP seems to act as a neurohormone on peripheral targets. On the basis of the analogy between the dorsal cells and the MIP-producing cells in L. stagnalis, it is proposed that the dorsal cells of P. corneus are involved in the control of body growth and associated processes.
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  • 32
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    Cell & tissue research 267 (1992), S. 483-492 
    ISSN: 1432-0878
    Keywords: Dental follicle ; Cell culture ; Fibroblasts ; Immunocytochemistry ; Ultrastructure ; Collagen ; Gel-electrophoresis ; Western blotting ; Rat (Sprague-Dawley)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Because the dental follicle is necessary for the eruption of teeth of limited eruption, it was the objective of this study to determine if the cells of the follicle could be cultured in vitro. To achieve this, dental follicles and associated enamel organs were dissected from the first and second mandibular molars of 6–7-day-old rats (secretory stage of amelogenesis), and then cultured in a medium that promotes fibroblast growth — the predominant cell type of the dental follicle. The cultured cells grew to confluency and were kept through 3 passages before experimentation. The cultured cells were fibroblastic in shape, elongate with processes, and transmission electron microscopy revealed that they contained an abundant rough endoplasmic reticulum, but did not form desmosomes. Immunofluorescent staining for anti-vimentin showed that all the cells stained and electron-microscopic immunogold labeling indicated that the antibody was associated with intermediate filaments. As revealed by SDS-polyacrylamide gel electrophoresis and Western blotting, the cultured cells synthesized and secreted the extracellular matrix molecules fibronectin and procollagens. Subsequent immunofluorescence staining of permeabilized and non-permeabilized cells confirmed the presence of fibronectin and type I collagen both intra- and extracellularly. Thus, based on all the above characteristics, the cultured cells appeared to be fibroblasts derived from the dental follicle, although a few of the fibroblasts may be derived from undifferentiated mesenchymal cells interposed between the alveolar bone and follicle. Experiments now can be conducted to determine how these cultured cells respond directly to growth factors that alter the rates of tooth eruption.
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  • 33
    ISSN: 1432-0878
    Keywords: Actin-like protein ; Fibronectin-like protein ; Regeneration ; Cell migration ; Immunocytochemistry ; Dugesia lugubris (Tricladida)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Actin- and fibronectin-like proteins were characterized in the planarian, Dugesia lugubris s.l., by sodium dodecyl sulphate polyacrylamide gel electrophoresis and immunoblotting analysis using antisera to vertebrate actin and fibronectin. These antisera recognized protein bands of 42 kDa and 220 kDa, respectively. In addition, the immunohistochemical distribution of both actin- and fibronectin-like material was examined by using immuno-electron microscopy. Actin-like protein was localized in myofibrils in various differentiation stages, and in the peripheral cytoplasm and lamellipodia of cells that were migrating. The fibronectin-like component was associated with the extracellular matrix in the fibrillar structures and with the surface of the migrating cells. Our data suggest that similar cellular and molecular mechanisms are involved in cell-matrix interactions and in the morphogenesis of living organisms at different evolutionary levels.
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  • 34
    ISSN: 1432-0878
    Keywords: Retina ; Dopaminergic neurons ; Synapses ; Inner plexiform layer ; Immunocytochemistry ; Electron microscopy ; Bufo marinus (Anura)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Tyrosine hydroxylase (TH) immunocytochemistry was utilized to quantify dopaminergic synapses in the inner plexiform layer of the retina of Bufo marinus. Since dopaminergic cells have bistratified dendritic arborisation in the inner plexiform layer, attention was given to the segregation of synapses between the scleral and the vitreal sublaminae. Light-microscopically, a more elaborate dendritic branching was observed in the scleral than in the vitreal sublamina. In contrast, about 55% of synapses occurred in the vitreal one fifth of the inner plexiform layer, 30% in the scleral fifth, and 15% in the intermediate laminae. Input sources and output targets showed only minor quantitative differences between sublaminae 1 and 5. TH-immunoreactive processes were found in presynaptic (62.8%) and postsynaptic (37.2%) positions. Synapses to the stained dendrites derived from bipolar (40.4%) and amacrine (59.6%) cells, whereas outputs from the TH-positive processes were directed to amacrine cells (56.8%) and to small and medium-sized dendrites (35.4%); at least some of these can be considered as ganglion cell dendrites. TH-positive profiles neither formed synapses with each other nor were presynaptic to bipolar cell terminals. Junctional appositions of the immunoreactive profiles were occasionally seen on non-stained amacrine and ganglion cell dendrites in the scleral sublamina of the inner plexiform layer and on optic axons in the optic fibre layer. Although dopaminergic cells are mainly involved in amacrine-amacrine interactions, inputs from bipolar terminals and outputs to ganglion cell dendrites were also substantial, suggestive of a role also in vertical information processing.
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  • 35
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    Cell & tissue research 268 (1992), S. 65-70 
    ISSN: 1432-0878
    Keywords: Stanniocalcin ; Corpuscles of Stannius ; Embryology ; Immunocytochemistry ; Pronephros ; Oncorhynchus keta (Teleostei)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary An immunocytochemical technique was used to follow the embryological origin and development of the corpuscles of Stannius (CS) in the chum salmon, Oncorhynchus keta. Stanniocalcin immunoreactive (ir-) cells can be observed as early as 13 days before hatching. The ir-CS cells appear in clusters of variable size in close association with nephric ducts. In addition, individual ir-cells also occur at this stage amoung epithelial cells of the nephric ducts. these individual cells may give rise to clusters which subsequently increase in size, the largest reaching 100 μm in diameter by the time of hatching. During this period, dispersed CS cells become evident and develop into secondary clusters in the vicinity of the primary clusters. These clusters appear to fuse to form larger clusters with a lobular structure. Transfer of the larvae (20 days after hatching) from fresh water to 50% seawater, accelerates the development of the CS tissue, suggesting an important role of the CS in seawater adaptation.
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  • 36
    ISSN: 1432-0878
    Keywords: Neuropeptide Y ; Brain, vertebrate ; Hypothalamus ; Pituitary gland, pars intermedia ; Nervus terminalis ; Immunocytochemistry ; Scyliorhinus torazame (Elasmobranchii)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Using a specific antiserum raised against synthetic neuropeptide Y, we examined the localization of immunoreactivity in the brain and hypophysis of the cloudy dogfish, Scyliorhinus torazame, by the peroxidase-antiperoxidase method. Immunoreactive perikarya were demonstrated in the ganglion of the nervus terminalis, the dorsocaudal portions of the pallium dorsale, the basal telencephalon, and the nucleus lateralis tuberis and the nucleus lobi lateralis in the hypothalamus. Labeled perikarya were also found in the tegmentum mesencephali, the corpus cerebelli, and the medulla oblongata. Some of the immunoreactive neurons in the hypothalamus were of the CSF-contacting type. The bulk of the labeled fibers in the nervus terminalis ran toward the basal telencephalon, showing radial projections and ramifications. Large numbers of these fibers coursed into the nucleus septi caudoventralis and the nucleus interstitialis commissurae anterioris, where they became varicose and occasionally formed fine networks or invested immunonegative perikarya. In the diencephalon, immunoreactive fibers were observed throughout the hypothalamus, e.g., in the pars neurointermedia of the hypophysis, the subependymal layer of the lobus inferior hypothalami, and in the neuropil of the posterior (mammillary) recess organ. Labeled fibers were scattered throughout the rest of the brain stem and were also seen in the granular layer of the cerebellum. These results suggest that, in the dogfish brain, neuropeptide Y or a related substance is involved in a variety of physiological processes in the brain, including the neuroendocrine control of the hypophysis.
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  • 37
    ISSN: 1432-0878
    Keywords: Olfactory epithelium ; Comparative study ; Histochemistry ; Immunocytochemistry ; Non-specific label ; Microsmatic fish ; Three-spined stickleback, Gasterosteus aculeatus (Teleostei) ; Nine-spined stickleback, Pungitius pungitius (Teleostei)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The olfactory epithelium of the three-spined stickleback (Gasterosteus aculeatus) and the nine-spined stickleback (Pungitius pungitius) has been studied with a conventional histochemical and a novel immunological staining technique. In both species, the sensory epithelium is arranged in folds separated by non-sensory epithelial tissue. In the nine-spined stickleback, intrinsic folds consisting of non-sensory cells are found in the apical part of the sensory epithelium where they divide the surface of the sensory epithelium into small islets. These non-sensory cells are non-ciliated, flattened and piled on top of each other; they contain numerous electron-translucent vesicles. The intrinsic folds are absent from the sensory epithelium of the three-spined stickleback. In both species, axons of receptor cells form a layer of fibers in the sensory epithelium immediately above the basal cells. In the three-spined stickleback, thick branches of the olfactory nerve are frequently found in this layer. These branches are only occasionally observed in the sensory epithelium of the nine-spined stickleback. Thus, the three-spined stickleback and the nine-spined stickleback show considerable differences in the organization of the sensory regions of the olfactory epithelium.
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  • 38
    ISSN: 1432-0878
    Keywords: Pituitary adenylate cyclase-activating peptide (PACAP) ; Immunocytochemistry ; Pancreas, endocrine, exocrine ; Insulin secretion ; Glucagon secretion ; Mouse (NMRI) ; Rat (Sprague-Dawley)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Pituitary adenylate cyclase-activating polypeptide (PACAP) is a neuropeptide that occurs in several tissues, e.g., in the gut. We have studied PACAP-like immunoreactivity in the pancreas of rat and mouse, and the effects of PACAP-38 on basal and stimulated insulin and glucagon secretion in the mouse. Immunofluorescence staining demonstrated the presence of PACAP-like immunoreactivity in nerve fibers in both the rat and mouse pancreas. The nerve fibers were seen in the exocrine pancreas and surrounding the islets. Occasionally, the nerve fibers occurred within the islets. Most PACAP-positive nerve fibers innervated the intrapancreatic ganglia, although no nerve cell bodies contained PACAP-like immunoreactivity. In-vivo experiments in mice revealed that basal plasma glucagon levels were increased by PACAP-39 injected intravenously at dose levels exceeding 1.8 nmol/kg. Furthermore, PACAP-38 (7 nmol/kg) potentiated the plasma glucagon response to the cholinergic agonist carbachol (0.16 μmol/kg). This potentiation was reduced to simple addition by pretreatment with a combined α- and β-adrenergic blockade by phentolamine (35 μmol/kg) and propranolol (8.5 μmol/kg). Moreover, PACAP-38 inhibited a carbachol-induced increase in the level of plasma insulin in the absence but not in the presence of adrenergic blockade. PACAP-38 increased basal plasma insulin levels and increased basal plasma glucose levels 6 min and 10 min, respectively, after injection of the peptide. We conclude that PACAP-like immunoreactivity exists in nerve fibers innervating the mouse and rat pancreas, particularly the intrapancreatic ganglia, and that PACAP-38 augments both basal and carbachol-stimulated glucagon secretion in the mouse.
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  • 39
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    Cell & tissue research 269 (1992), S. 315-322 
    ISSN: 1432-0878
    Keywords: Calcitonin gene-related peptide ; Islet amyloid polypeptide ; Immunocytochemistry ; Pancreas endocrine, exocrine ; Rat (Sprague-Dawley) ; Mouse (NMRI)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary It was previously demonstrated that the two chemically related peptides calcitonin gene-related peptide (CGRP) and islet amyloid polypeptide (IAPP) both occur in the pancreas. We have now examined the cellular localization of CGRP and IAPP in the rat and the mouse pancreas. We found, in both the rat and the mouse pancreas, CGRP-immunoreactive nerve fibers throughout the parenchyma, including the islets, with particular association with blood vessels. CGRP-immunoreactive nerve fibers were regularly seen within the islets. In contrast, no IAPP-immunoreactive nerve fibers were demonstrated in this location. Furthermore, in rat islets, CGRP immunoreactivity was demonstrated in peripherally located cells, constituting a major subpopulation of the somatostatin cells. Such cells were lacking in the mouse islets. IAPP-like immunoreactivity was demonstrated in rat and mouse islet insulin cells, and, in the rat, also in a few non-insulin cells in the islet periphery. These cells seemed to be identical with somatostatin/CGRP-immunoreactive elements. In summary, the study shows (1) that CGRP, but not IAPP, is a pancreati neuropeptide both in the mouse and the rat; (2) that a subpopulation of rat somatostatin cells contain CGRP; (3) that mouse islet endocrine cells do not contain CGRP; (4) that insulin cells in both the rat and the mouse contain IAPP; and (5) that in the rat, a non-insulin cell population apparently composed of somatostatin cells stores immunoreactive IAPP. We conclude that CGRP is a pancreatic neuropeptide and IAPP is an islet endocrine peptide in both the rat and the mouse, whereas CGRP is an islet endocrine peptide in the rat.
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  • 40
    ISSN: 1432-0878
    Keywords: Growth hormone ; Prolactin ; Gonadotropin ; Adrenocorticotropin ; Immunocytochemistry ; Pituitary gland ; Sparus auratus (Teleostei)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The chronological appearance of endocrine cells in the pituitary of sea-bream (Sparus auratus) larvae was studied using antisera against salmon prolactin, trout growth hormone, salmon gonadotropin and N-terminal human adrenocorticotropin. The larval pituitary (1–12 days after hatching) was oval in shape and was composed of a dense mass of cells with few neurohypophysial fibres. By 60 days after hatching it began to resemble the adult and was divisible into a distinct rostral pars distalis containing prolactin and adrenocorticotropin cells; a proximal pars distalis containing somatotrophs and gonadotrophs and a pars intermedia. Cells immunoreactive with antisera against growth hormone were observed immediately after hatching (2 days post-fertilization). Weakly staining prolactin cells were observed 2 days later in the region corresponding to the rostral pars distalis. Cells immunoreactive with anti-gonadotropin and anti-adrenocorticotropin sera were observed in the pituitary 6 and 8 days after hatching, respectively. All the cell-types studied were immunoreactive from the time they were first identified until the final samples 90 days after hatching.
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  • 41
    ISSN: 1432-0878
    Keywords: Dental pulp ; Laminin ; Collagen IV ; Odontoblast ; Nerve regeneration ; Immunocytochemistry ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The distribution of laminin-like immunoreactivity in adult normal and denervated cat mandibular tooth pulps was studied by the use of fluorescence microscopy and pre-embedding immunogold electron microscopy. Immunoreactivity to collagen IV was also assessed in order to distinguish basement membranes. In normal pulps, light-microscope laminin-like immunoreactivity was strong along blood vessels and Schwann cell sheaths, and a faint immunoreactivity was seen also in the odontoblast layer. Electron microscopy confirmed the laminin-like immunoreactivity of endothelial and Schwann cell basement membranes at all pulpal levels. In the odontoblast layer and the predentine, nerve-like structures lacking basement membranes but possessing strong membrane laminin-like immunoreactivity were encountered. In addition, a clear-cut laminin-like immunoreactivity of plasma membranes of the somata and processes of odontoblasts was seen. Observations on denervated pulps as well as pulps in which nerve regeneration had taken place did not reveal any changes in the pattern of laminin-immunoreactivity in basement membranes or odontoblasts. Distribution of collagen IV-like immunoreactivity was very similar to laminin-like immunoreactivity in basement membranes of blood vessels and Schwann cells, and appeared unaffected by denervation. The odontoblasts and nerve-like profiles in the odontoblast layer were devoid of collagen IV-like immunoreactivity. We propose that odontoblast-associated laminin could be of significance as guidance for regenerating terminal pulpal nerve fibers to appropriate targets.
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  • 42
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    Cell & tissue research 270 (1992), S. 47-56 
    ISSN: 1432-0878
    Keywords: Cilia ; Microvilli ; Secretory granules ; Mucus ; Freeze-substitution ; Immunocytochemistry ; Rana pipiens (Anura)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary This study showed that the olfactory mucus is a highly structured extracellular matrix. Several olfactory epithelial glycoconjugates in the frog Rana pipiens were localized ultrastructurally using rapid-freeze, freeze-substitution and post-embedding (Lowicryl K11M) immunocytochemistry. Two of these conjugates were obtained from membrane preparations of olfactory cilia, the glycoproteins gp95 and olfactomedin. The other conjugates have a carbohydrate group which in the olfactory bulb appears to be mostly on neural cell-adhesion molecules (N-CAMs); in the olfactory epithelium this carbohydrate is present on more molecules. Localization of the latter conjugates was determined with monoclonal antibodies 9-OE and 5-OE. Ultrastructurally all antigens localized in secretory granules of apical regions of frog olfactory supporting cells and in the mucus overlying the epithelial surface, where they all had different, but partly overlapping, distributions. Monoclonal antibody 18.1, to gp95, labeled the mucus throughout, whereas poly- and monoclonal anti-olfactomedin labeled a deep mucous layer surrounding dendritic endings, proximal parts of cilia, and supporting cell microvilli. Labeling was absent in the superficial mucous layer, which contained the distal parts of the olfactory cilia. Monoclonal antibody 9-OE labeled rather distinct areas of mucus. These areas sometimes surrounded dendritic endings and olfactory cilia. Monoclonal antibody 5-OE labeled membranes of dendritic endings and cilia, and their glycocalyces, and also dendritic membranes.
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  • 43
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    Cell & tissue research 270 (1992), S. 601-607 
    ISSN: 1432-0878
    Keywords: Dopamine ; HPLC ; Immunocytochemistry ; Hydra attenuata (Cnidaria)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary High performance liquid chromatography (HPLC), with electrochemical detection, is an analytical method sensitive enough to permit quantification of dopamine, dihydroxyphenylalanine (DOPA) and 5-S-cysteinyl DOPA in single or hemisected specimens ofHydra attenuata. Dopamine and 5-S-cysteinylDOPA appear to be the quantitatively predominant catechol compounds inH. attenuata, whereas DOPA is present in minor amounts. The presence of DOPA and 5-S-cysteinylDOPA, and the quantitative correlation between dopamine and these compounds in many specimens, suggests that dopamine inH. attenuata, as in higher animals, is formed through decarboxylation of DOPA. Contrary to the dopaminergic nerves in higher animals, DOPA inHydra seems to be oxidized and 5-S-cysteinyl DOPA is formed as a by-product. The oxidation of DOPA indicates that the hydroxylation of tyrosine into DOPA in the tissues ofH. attenuata is mediated by a tyrosinase rather than a tyrosine hydroxylase. Immunocytochemical methods demonstrate a highly variable distribution of dopamine in the tissues of different specimens ofH. attenuata. Dopamine immunoreactivity is confined to ectodermal tissue and can be found in several different cell types including nerve cells, battery cells, nematocytes, epithelial cells and interstitial undifferentiated cells. The large amounts of dopamine found in some specimens ofH. attenuata indicate some biological function, although its sporadic occurrence in neurites makes it less plausible as a generally utilized neurotransmitter in this animal.
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  • 44
    ISSN: 1432-0878
    Keywords: Gastrin ; Gastrin-releasing peptide ; Neurotensin ; Vasoactive intestinal peptide ; Immunocytochemistry ; Harderian gland ; Rana esculenta (Anura)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The presence and distribution of gastrin-, gastrin-releasing peptide-, neurotensin-and vasoactive intestinal polypeptide-like immunoreactivity in the Harderian gland ofRana esculenta were studied at different times of the annual cycle. Gastrin-releasing peptide, neurotensin and vasoactive intestinal polypeptide-like substances were found either in the glandular cells, or in the nerve fibers surrounding the glandular acini. Gastrin-like immunoreactivity was confined to the glandular cells. The immunoreactivity varied during the annual cycle, with the greatest concentration being noted during the recovery phase of glandular secretory activity.
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  • 45
    ISSN: 1432-0878
    Keywords: Immunocytochemistry ; Serotonin ; RFamide ; Development ; Paraspadella gotoi (Chaetognatha)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The distribution and development of serotonin-and RFamide-like immunoreactivities in the nervous system of Chaetognatha, Paraspadella gotoi, were examined in whole-mount preparations. In adults, a single serotonin-like immunoreactive (5HTLI) neuron and numerous RFamide-like immunoreactive (RFaLI) neurons were found in the central nervous system. Based on the structure of the fins, hooks, and eyes, seven postembryonic developmental stages were recognized. The most obvious features of the stages are: stage 1, newly hatched young; stage 2, elongation of a continuous lateral tail fin; stage 3, separation of the lateral and tail fins; stage 4, appearance of hooks; stage 5, pigmentation of eyes, stage 6, attachment by tail adhesive fins; stage 7, prey capture. Stage 1 did not show any immunoreactivity. The 5HTLI neuron first appeared at stage 4 and its axonal pathway became similar to the adult at stage 6. On the other hand, the RFaLI neurons appeared at stage 3 in the ventral ganglion. Some of their somata disappeared at stage 5 and the neuronal architecture resembled the adult at stage 7 although the RFaLI neurons in the cerebral ganglion were complete at the juvenile stage.
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  • 46
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    Cell & tissue research 267 (1992), S. 209-214 
    ISSN: 1432-0878
    Keywords: Testis ; Sulfhydryl oxidase ; Hypospermatogenesis ; Sertoli cell integrity ; Immunocytochemistry ; Man
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Sulfhydryl oxidase (SOx) immunoreactivity was investigated in the seminiferous epithelium of human biopsy material from the testes of 33 adult men with disturbed fertility. SOx immunoreactivity was expressed in normal seminiferous epithelium in type-A spermatogonia (27±4% of all spermatogonia) (n=4), in spermatocytes and round spermatids. Mature spermatozoa as well as Sertoli cells were unlabelled. within the interstitium, Leydig cells were immunopositive. In biopsies of oligozoospermic men showing hypospermatogenesis (n=24), an increase in labelled spermatogonia up to more than 90% was observed in biopsies, where seminiferous epithelia revealed only spermatogonia and Sertoli cells. Within the group of oligozoospermic patients there was a significant increase of labelled spermatogonia from 43±13% (〉20 mill/ejaculate) (n=7) to 55±16% ( 20 and 〉20 mill/ejaculate) (n=6) to 68±8% (〈5 mill/ejaculate) (n=11) and a significant (P=0.01) decrease of score count from 7.0±2.7 to 2.0±1.8. In this group the increase of labelled spermatogonia was correlated with sperm concentrations in the ajaculate (correlation coefficient: r=-0.6). In biopsies of azoospermic patients showing maturation arrest at the level of spermatocytes or spermatids (n=5) the percentage of labelled spermatogonia was within the range of 24% to 59%. Immunoreactivity in Sertoli cells was only found in single degenerating cells and in tubules showing Sertoli Cell Only Syndrome (SCO) without lumen formation. Sertoli cells within immature seminiferous cords were immunonegative, indicating that Sertoli cell SOx immunoreactivity is rather a sign of physiological alterations in degenerating cells than dependent on the stage of differentiation. Leydig cells did not show changes of immunoreactivity in any biopsy. It is concluded that SOx expression in spermatogonia may serve as a marker for spermatogenic efficiency.
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  • 47
    ISSN: 1432-0878
    Keywords: α-Subunit ; Pituitary glycoprotein hormone ; PRL cell ; Pars distalis ; Colocalization ; Immunocytochemistry ; Bullfrog, Rana catesbeiana (Anura)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Our recent finding that the number of immunoreactive α-subunit cells was invariably greater than the total number of immunoreactive gonadotropin (GTH) and thyrotropin (TSH) cells in the bullfrog (Rana catesbeiana) pituitary gland raises the possibility that the α-subunit also exists in pituitary cells other than GTH and TSH cells. The present study demonstrates that there are a considerable number of immunoreactive prolactin (PRL) cells that are also stained with antibody against the α-subunit when adjacent sections are immunocytochemically examined. Neither immunoreactive growth hormone nor adrenocorticotropin cells are stained with the antibody against the α-subunit. The specificity of the antibody against the α-subunit and of that against PRL was demonstrated by preabsorption test, non-competitive binding test, and immunoblot analysis. Double-immunolabeling with gold particles of different sizes for the α-subunit and PRL revealed that most of the immunolabeled PRL-secretory granules are also labeled with the α-subunit antibody. The gold particles indicating the presence of the α-subunit were mostly found in the peripheral zone of the secretory granules.
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  • 48
    ISSN: 1432-0878
    Keywords: Nervous system, central ; VD1/RPD2 system ; Neuropeptide immunocytochemistry ; Hybridization, in situ ; Immunocytochemistry ; Lymnaea stagnalis (Mollusca)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary VD1 and RPD2 are two giant neuropeptidergic neurons in the central nervous system (CNS) of the pond snail Lymnaea stagnalis. We wished to determine whether other central neurons in the CNS of L. stagnalis express the VD1/RPD2 gene. To this end, in situ hybridization with the cDNA probe of the VD1/RPD2 gene and immunocytochemistry with antisera specific to VD1 and RPD2 (the α1-antiserum, Mab4H5 and ALMA 6) and to R15 (the α1 and 16-mer antisera) were performed on alternate tissue sections. A VD1/RPD2 neuronal system comprising three classes of neurons (A1–A3) was found. All neurons of the system express the gene. Division into classes is based on immunocytochemical characteristics. Class A1 neurons (VD1 and RPD2) immunoreact with the α1-antiserum, Mab4H5 and ALMA 6. Class A2 neurons (1–5 small and 1–5 medium sized neurons in the visceral and right parietal ganglion, and two clusters of small neurons and 5 medium-sized neurons in the cerebral ganglia) immunoreact with the α1-antiserum and Mab4H5, but not with ALMA 6. Class A3 neurons (3–4 medium-sized neurons and a cluster of 4–5 small neurons located in the pedal ganglion) immunoreact with the α1-antiserum only. All neurons of the system are immunonegative to the R15 antisera. The observations suggest that the neurons of the VD1/RPD2 system produce different sets of neuropeptides. A group of approximately 15 neurons (class B), scattered in the ganglia, immunostained with one or more of the antisera, but did not react with the cDNA probe in in situ hybridization.
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  • 49
    ISSN: 1432-0878
    Keywords: Nervous system, central ; Ganglia, invertebrate ; Octopamine ; Immunocytochemistry ; DUM neurone ; Neurosecretion ; Gryllus bimaculatus (Insecta)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The distribution of octopamine-immunoreactive neurons is described using whole-mount preparations of all central ganglia of the cricket, Gryllus bimaculatus. Up to 160 octopamine-immunoreactive somata were mapped per animal. Medial unpaired octopamine-immunoreactive neurons occur in all but the cerebral ganglia and show segment-specific differences in number. The position and form of these cells are in accordance with well-known, segmentally-organized clusters of large dorsal and ventral unpaired medial neurons demonstrated by other techniques. In addition, bilaterally arranged groups of immunoreactive somata have been labelled in the cerebral, suboesophageal and terminal ganglia. A detailed histological description of octopamine-immunoreactive elements in the prothoracic ganglion is given. Octopamine-immunoreactive somata and axons correspond to the different dorsal unpaired medial cell types identified by intracellular single-cell staining. In the prothoracic ganglion, all efferent neurons whose primary neurites are found in the fibre bundle of dorsal unpaired cells are immunoreactive. Intersegmental octopamine-immunoreactive neurons are also present. Collaterals originating from dorsal intersegmental fibres terminate in different neuropils and fibre tracts. Fine varicose fibres have been located in several fibre tracts, motor and sensory neuropils. Peripheral varicose octopamine-immunoreactive fibres found on several nerves are discussed in terms of possible neurohemal releasing sites for octopamine.
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  • 50
    ISSN: 1432-0878
    Keywords: Immunocytochemistry ; Enkephalin ; Skin ; Touch dome ; Merkel cells ; Dense-core granules ; Mammalian species
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Immunogold staining failed to show met-enkephalin immunoreactivity in the Merkel cell dense-core granules of rats when examined by electron microscopy, but showed gold particle staining in the Merkel cell dense-core granules of mice and nude mice. Merkel cells of hamster, guinea pig, rabbit, cat and dog were also examined using a similar method, and different antisera dilutions. Immunogold particles were consistently found in the dense-core granules of mice and nude mice at all antisera dilutions, but not in the other species, except in the dog, where a very low labelling response was encountered. Merkel cells from skin touch domes or sinus hair follicles, did not exhibit any difference in peptide expression as far as met-enkephalin immunoreactivity was concerned. In addition, all species studied, including mice and nude mice, did not show leu-enkephalin immunoreactivity in their Merkel cell dense-core granules. It is concluded that species variability in peptide expression occurs in the Merkel cell dense-core granules, and may be closely related to the different methodologies used.
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  • 51
    ISSN: 1432-0878
    Keywords: Pheromone-biosynthesis-activating neuropeptide ; Immunocytochemistry ; Helicoverpa zea (Insecta)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Production of sex pheromone in several species of moths has been shown to be under the control of a neuropeptide termed pheromone-biosynthesis-activating neuropeptide (PBAN). We have produced an antiserum to PBAN from Helicoverpa zea (Lepidoptera: Noctuidae) and used it to investigate the distribution of immunoreactive peptide in the brain-suboesophageal ganglion complex and its associated neurohemal structures, and the segmental ganglia of the ventral nerve cord. Immunocytochemical methods reveal three clusters of cells along the ventral midline in the suboesophageal ganglion (SOG), one cluster each in the presumptive mandibular (4 cells), maxillary (12–14 cells), and labial neuromeres (4 cells). The proximal neurites of these cells are similar in their dorsal and lateral patterns of projection, indicating a serial homology among the three clusters. Members of the mandibular and maxillary clusters have axons projecting into the maxillary nerve, while two additional pairs of axons from the maxillary cluster project into the ventral nerve cord. Members of the labial cluster project to the retrocerebral complex (corpora cardiaca and cephalic aorta) via the nervus corpus cardiaci III (NCC III). The axons projecting into the ventral nerve cord appear to arborize principally in the dorsolateral region of each segmental ganglion; the terminal abdominal ganglion is distinct in containing an additional ventromedial arborization in the posterior third of the ganglion. Quantification of the extractable immunoreactive peptide in the retrocerebral complex by ELISA indicates that PBAN is gradually depleted during the scotophase, then restored to maximal levels in the photophase. Taken together, our findings provide anatomical evidence for both neurohormonal release of PBAN as well as axonal transport via the ventral nerve cord to release sites within the segmental ganglia.
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  • 52
    ISSN: 1432-0878
    Keywords: Dermis ; Collagen fibers ; Extracellular matrix ; Fibronectin ; Immunocytochemistry ; Man
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The distribution of collagen types I, III, IV, and of fibronectin has been studied in the human dermis by light and electron-microscopic immunocytochemistry, using affinity purified primary antibodies and tetramethylrhodamine isothiocyanate-conjugated secondary antibodies. Type I collagen was present in all collagen fibers of both papillary and reticular dermis, but collagen fibrils, which could be resolved as discrete entities, were labeled with different intensity. Type III collagen codistributed with type I in the collagen fibers, besides being concentrated around blood vessels and skin appendages. Coexistence of type I and type III collagens in the collagen fibrils of the whole dermis was confirmed by ultrastructural double-labelling experiments using colloidal immunogold as a probe. Type IV collagen was detected in all basement membranes. Fibronectin was distributed in patches among collagen fibers and was associated with all basement membranes, while a weaker positive reaction was observed in collagen fibers. Ageing caused the thinning of collagen fibers, chiefly in the recticular dermis. The labeling pattern of both type I and III collagens did not change in skin samples from patients of up to 79 years of age, but immunoreactivity for type III collagen increased in comparison to younger skins. A loss of fibronectin, likely related to the decreased morphogenetic activity of tissues, was observed with age.
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  • 53
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    Cell & tissue research 270 (1992), S. 113-124 
    ISSN: 1432-0878
    Keywords: Dopamine ; Nervous sytem, insect ; Ganglia, invertebrate ; Immunocytochemistry ; Schistocerca gregaria (Insecta)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The distribution of dopamine-like immunoreactivity in somata and neurites within the thoracic and abdominal nervous system of the locust Schistocerca gregaria was mapped using two polyclonal antibodies. The prothoracic ganglion contains three bilateral pairs of immunoreactive somata. Two of these lie close to the root of the anterior connective while the third lies between the somata of anterior and common inhibitory motor neurones. The primary neurites of the third pair have a distinctive branching pattern that can be followed through the neuropile and gives rise to a large descending axon. The mesothoracic ganglion has a single pair of antero-lateral immunoreactive somata but the metathoracic and fourth abdominal ganglia have none. The fifth, sixth, and seventh abdominal ganglia each have one pair of somata which are situated at the root of the sternal nerve while the terminal ganglion has a similar pair in the eighth neuromere only. Seven to ten immunoreactive axons enter each ganglion from each of the connectives. Some of these can be traced along the longitudinal tracts that traverse the neuropile. In each ganglion there is one axon in the median dorsal tract and two in ventral median tract. In the meso- and metathoracic ganglia an additional large axon is seen in lateral dorsal tract and dorsal intermediate tract. The axons in median dorsal, and dorsal intermediate tracts send out long ventro-lateral and ventro-medial branches which extend throughout much of the neuropile. Those in median ventral tract send markedly varicose branches to the ventral and dorsal edges of the medial neuropile.
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  • 54
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    Cell & tissue research 270 (1992), S. 339-352 
    ISSN: 1432-0878
    Keywords: Endocrine pancreas ; Ontogeny ; Regulatory peptides ; Immunocytochemistry ; Dicentrarchus labrax (Teleostei)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The development of the endocrine pancreas of the teleost sea bass (Dicentrarchus labrax, L.) was examined from hatching to 61 days, using the peroxidase-antiperoxidase technique for light microscopy. Mammalian and bonito insulin (mI and bI)-, salmo somatostatin-25 (SST-25)-, somatostatin-14 (SST-14a and b)-, glucagon-, bovine pancreatic polypeptide (PP)-, peptide tyrosine-tyrosine (PYY)- and salmo neuropeptide Y (NPY)-like immunoreactivity was demonstrated. Four ontogenetic stages were established according to the organization and immunostaining of the endocrine cells. One cell strand or primordial cord showing mI/bI- and SST-25/SST-14a-like immunoreactivity was first found at hatching in the dorsal epithelium of the anterior zone of the midgut (stage 1). One primitive islet, comprising outer SST-25/SST-14a- and inner mI/bI- and SST-14a/ SST-14b-immunoreactive cells, was found in 2- to 5-day-old larvae (stage 2). One single islet, in which glucagon-immunoreactive cells appear in the periphery, was found in larvae from 9 to 20 days after hatching (stage 3). One big islet containing, in addition, PP-immunoreactive cells in the outer region and slender cell processes which showed PYY-like immunoreactivity, was found from 25 to 61 days after hatching. During this period, primordial islets, composed of SST-25- and bI-immunoreactive cells, and clustered or isolated pancreatic endocrine cells, close to the pancreatic duct, as well as small and intermediate islets (secondary islets), in which glucagon, PP, PYY and NPY seem to be co-localized, were progressively found (stage 4). The origin of the endocrine pancreas of sea bass, and the ontogenetic and phylogenetic significance, are discussed.
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  • 55
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    Cell & tissue research 270 (1992), S. 383-393 
    ISSN: 1432-0878
    Keywords: Gonadotropin-releasing hormone ; Immunocytochemistry ; Annual cycle-Mink ; Mustela vison
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The distribution of gonadotropin-releasing hormone-immunoreactive neurons and processes was mapped in the female mink brain using coronal, horizontal and sagittal sections. Perikarya were found along a ventral continuum including the olfactory tubercle, the diagonal band of Broca, the lateral septum, the preoptic and anterior hypothalamic area and the mediobasal hypothalamus; 80% of the perikarya were counted in the mediobasal hypothalamus. Fibres were mainly observed in the organum vasculosum of the lamina terminalis and the median eminence. A few processes terminated in the ependymal cells lining the third and lateral ventricles. The total number of immunoreactive perikarya was the highest in the brains of females sacrificed in July; it then significantly decreased until December. This variation is discussed in relation to the annual breeding cycle.
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  • 56
    ISSN: 1432-0878
    Keywords: Ameloblasts ; Differentiation ; Proliferation ; Bromodeoxyuridine ; Enamel matrix proteins ; Immunocytochemistry ; Rat (Wistar)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A double-staining immunocytochemical technique was used for the simultaneous detection, at the light- and electron-microscopical level, of proliferating bromodeoxyuridine (BrdU)-labelled cells and enamel protein (EP)-producing cells in the inner enamel epithelium (IEE) of rat tooth germ. BrdU-positive cells were found in the region of the IEE close to the cervical loop and never displayed EP-like immunoreactivity. BrdU-immunoreactivity was confined to the nucleus of replicating cells. In contrast, epithelial cells displaying EP-like immunoreactivity were found in the region of the forming dental cusp and were consistently BrdU-negative. EP-like immunoreactivity was detectable in the cytoplasmic compartments involved in the exocrine secretion pathway and in the extra-cellular matrix close to EP-immunoreactive cells. These data support the view that withdrawal from the cell cycle in the IEE is a temporal prerequisite for acquiring the functional competence of secreting EP. Moreover, cycling cells and secretory cells in the IEE constitute two separate compartments that are spatially defined, and that exhibit clear-cut staining patterns with respect to BrdU- and EP-immunoreactivity, respectively. We thus propose that BrdU-incorporation and EP-production may be used as specific markers of the differentiation of the IIE cells in studies of the possible role of growth factors, their receptors and oncoproteins in this tissue.
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  • 57
    ISSN: 1432-0878
    Keywords: Neuropeptides ; Neuropeptide Y ; FMRFamide ; Immunocytochemistry ; Telencephalon ; Thalamus ; Salmo salar (Teleostei)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The colocalization of the peptides neuropeptide Y (NPY) and Phe-Met-Arg-Phe-NH2 (FMRFamide) in the brain of the Atlantic salmon was investigated with double immunofluorescence labeling and peroxidase-antiperoxidase immunocytochemical techniques. Colocalization of NPY-like and FMRE amide-like immunoreactivities was observed in neuronal cell bodies and fibers in four brain regions: in the lateral and commissural nuclei of the area ventralis telencephali, in the nucleus ventromedialis thalami, in the laminar nucleus of the mesencephalic tegmentum, and in a group of small neurons situated among the large catecholaminergic neurons in the isthmal region of the brainstem. All cell bodies in these nuclei were immunoreactive to both NPY and FMRF. We consistently observed larger numbers of FMRF-immunoreactive than NPY-immunoreactive fibers. In the nucleus ventromedialis thalami NPY- and FMRFamide-like immunoreactivities were colocalized in cerebrospinal fluid (CSF)-contacting neurons. NPY-immunoreactive, but not FMRF-immunoreactive, neurons were found in the stratum periventriculare of the optic tectum, and at the ventral border of the nucleus habenularis (adjacent to the nucleus dorsolateralis thalami). Neurons belonging to the nucleus of the nervus terminalis were FMRF-immunoreactive but not NPY-immunoreactive. The differential labeling indicates, as do our cross-absorption experiments, that the NPY and FMRFamide antisera recognize different epitopes. Thus, it is probable that NPY-like and FMRFamide-like substances occur in the same neurons in some brain regions.
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  • 58
    ISSN: 1432-0878
    Keywords: Ganglia, invertebrate ; Neurosecretory cells ; DUM neurone ; Neurohemal organs ; Heart ; Immunocytochemistry ; Locusta migratoria (Insecta)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Three antisera were used to study the distribution and anatomy of bovine pancreatic polypeptide (BPP)-like/FMRFamide-like immunoreactive neurones within the unfused abdominal ganglia of the migratory locust, Locusta migratoria. All the antisera used stained two or more clusters of perikarya, localized anteriorly and posteriorly near the midline within each unfused abdominal ganglion. Double labelling experiments with intracellular dye injection, or differential backfilling, combined with subsequent immunostaining were carried out to identify these neurones. Two of the antisera (antisera 1 and 2, both raised against FMRFamide) stained three groups of midline neurones, located anterior dorsal, anterior ventral and posterior dorsal within the ganglion. Neurones of the former of these two clusters projected via the anterior median nerve to a neurohaemal organ. The posterior cluster of midline cells comprised immunopositive perikarya all but one of which also projected via the anterior median nerve to innervate the neurohaemal organ. Double labelling with Lucifer yellow and antisera 1 and 2 showed that the remaining neurone was the previously identified doral unpaired median (DUM)heart1 neurone. The third antiserum (AK141), also raised against FMRFamide, stained neurones within an anterior dorsal cluster, and in a posterior cluster. Double labelling with differential Co2+/Ni2+-backfilling and the antiserum 3 (AK141) demonstrated that the large neurones of both clusters belonged to the population of bilaterally projecting neurones (BPNs), including the DUMheart1 neurone. Since the antisera cross-react with BPP and fail to label neurones when preadsorped with BPP or FMRFamide, we conclude that the labelled neurones contain polypeptides of the FMRFamide/BPP-family.
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  • 59
    ISSN: 1432-0878
    Keywords: Corpuscles of Stannius ; Stanniocalcin ; Immunocytochemistry ; Western blot ; Amia calva (Holostei)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary We used an antiserum against salmon stanniocalcin in an immunohistochemical, immunocytochemical, and Western blot analysis of bowfin (Amia calva) corpuscles of stannius. The bowfin is one of two extant holostean species with ancient ancestral links to modern-day bony fishes. The corpuscles of Stannius (white corpuscles) of the bowfin were scattered throughout much of the kidney among the adrenocortical homolog (yellow corpuscles) but could be distinguished from the adrenocortical homolog by their positive staining with both the periodic acid-Schiff reaction and a salmon stanniocalcin antiserum. Immunoreactivity was confined to cytoplamic granules and was absent when the antiserum was blocked with salmon stanniocalcin or with a crude extract of bowfin corpuscles of Stannius. When bowfin corpuscle-of-Stannius extracts were subjected to sodium dodecyl sulphate electrophoresis and Western blot analysis, two closely spaced bands were evident (43–45 kDa). Staining of both bands was abolished by pre-absorption of the antiserum with salmon stanniocalcin. In comparison to salmon stanniocalcin, the reputed bowfin hormone migrated faster in gels, suggesting a smaller apparent size. The purification of bowfin stanniocalcin should yield important new information regarding the evolution of this unique calcium-regulating hormone.
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  • 60
    ISSN: 1432-0878
    Keywords: Histamine ; Biochemistry ; Immunocytochemistry ; Retina ; Photoreceptors ; Paraboloid ; Turtle, Pseudemys scripta (Chelonia)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A combination of immunocytochemical and biochemical methods was used to study histamine in the turtle retina. Histamine-like immunoreactivity was localized within paraboloids of certain cone photoreceptors by use of two different antisera directed against histamine. Preincubation of eyecups in Ringer's containing 10 μM histamine selectively increased the immunoreactivity of these photoreceptor paraboloids. The present localization of histamine in paraboloids indicated that, although histamine is in photoreceptors of the turtle retina, it may play some metabolic or neuromodulatory role, and not function as a neurotransmitter.
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  • 61
    ISSN: 1432-0878
    Keywords: Alcohol dehydrogenase (ADH) ; Oogenesis ; Vitellogenesis ; Yolk ; Immunocytochemistry ; Drosophila melanogaster (Insecta)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The use of monoclonal antibodies against Drosophila alcohol dehydrogenase (ADH) provides a powerful tool in the analysis of the tissue and temporal patterns of Adh gene expression. Immunocytochemical techniques at the light- and electron-microscopic levels have been used to determine the distribution of ADH in the ovarian follicles of D. melanogaster during oogenesis. In the early stages of oogenesis, small amounts of ADH are detectable in the cystocytes. At the beginning of vitellogenesis (S7), ADH appears to be located mainly in the nurse cells. From stage S9 onwards, the ADH protein is evenly distributed in the ooplasm until the later stages of oogenesis (S13–14), when multiple ADH-positive bodies of varying size appear in the ooplasm. This change in distribution is a result of the compartmentalization of the ADH protein within the glycogen yolk or β-spheres. Yolk becomes enclosed within the lumen of the primitive gut during embryonic development, and thus our results suggest a mechanism for the transfer of maternally-inherited enzymes to the gut lumen via yolk spheres.
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  • 62
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    Cell & tissue research 268 (1992), S. 277-281 
    ISSN: 1432-0878
    Keywords: Lung ; Elastin-binding protein ; Lectins ; Galactose ; Monocytes ; Immunocytochemistry ; Rat (Wistar)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary 67 kDa elastin-binding protein (RL-67EBP) has been isolated from neonatal rat lungs by the use of an elastin-coupled affinity column, followed by elution with either lactose or synthetic elastin hexapeptide (VGVAPG), and immunohistochemistry has been used on perinatal rat lungs to determine the tissue localization of this protein. No immunoreactive structures occur in fetal lungs, or in the lungs of day-1 and-4 neonates. On day-7 after birth, immunoreactive cells appear in the subepithelial connective tissue of the intrapulmonary airways, from day-10 on, these cells become evenly distributed in the alveolar parenchyma. Occasionally, some cells occur in the alveolar air space, being free from the surface of the alveolar septum. Unpermeabilized cells obtained by bronchoalveolar lavage, show cell surface immunoreactivity, indicating that RL-67EBP is expressed on the surface membrane of the cells. From these findings, it is suggested that the immunoreactive cells are blood-borne monocytes, and that RL-67EBP may function as an elastin peptide receptor by which monocytes mobilize through interstitial connective tissue during their migration from blood to alveolar air space, where they eventually differentiate into alveolar macrophages.
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  • 63
    ISSN: 1432-0878
    Keywords: Neurosecretory cells ; Brain ; Immunocytochemistry ; Prothoracicotropic hormone ; Insulin-related peptide ; Neuroparsins ; Locusta migratoria (Insecta)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Using a monoclonal antibody directed against a synthetic pentadecapeptide corresponding to the N-terminus of the prothoracicotropic hormone (PTTH) of Bombyx mori, we report the presence of immunoreactive molecules in a large number of median neurosecretory cells of the pars intercerebralis of the migratory locust, Locusta migratoria. These cells correspond to the A1 cell type which we show to contain also neuroparsins, a family of predominant neurohormones of the migratory locust. In contrast, PTTH-like molecules are absent from A2 cells of the pars intercerebralis which contain Locusta insulin-related peptide (LIRP). Developmental studies show the presence of PTTH-related substances in neurosecretory cells of Locusta migratoria from late embryogenesis to adult development, including ageing vitellogenic female adults.
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  • 64
    ISSN: 1432-0878
    Keywords: Sodium influx-stimulating (SIS) peptide ; Na+ transport ; In situ hybridization ; Immunocytochemistry ; Lymnaea stagnalis (Mollusca)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The functional morphology of the neuroendocrine system producing sodium influx-stimulating (SIS) peptide in the pond snail, Lymnaea stagnalis, was studied by in situ hybridization and immunocytochemistry. The SIS-peptide, which is 76 amino acids long, stimulates sodium uptake from the ambient medium. Two synthetic DNA probes were used for in situ hybridization. The nucleotide sequences were chosen from the cDNA structure; they encode amino acids 8–17 and 64–73, respectively. SIS-peptide sequences 10–20 and 67–76 were synthesized and antibodies were raised to them and affinity-purified. In addition to these antibodies, a monoclonal antibody raised to a bioactive, high-pressure liquid chromatography (HPLC)-purified brain extract was used for immunocytochemistry. Paraffin sections of central nervous systems and of whole snails were studied. The SIS-peptide system could be identified as the previously described yellow cell (YC) system by comparing alternate sections treated with the DNA probes, stained with the antibodies, or stained with alcian blue-alcian yellow. SIS-peptide neurons (∼45) occur in the ganglia of the visceral ring and in the proximal parts of visceral nerves. Axons run in the nerves of these and in several nerves of other ganglia. Numerous axon branches penetrate the perineurium forming a vast central neurohemal area. The SIS-peptide system innervates the pericardium, the nephridial gland, the reno-pericardial canal, the ureter, the spermoviduct and gonadal acini, the anterior aorta, the ventral buccal artery, and the penis protractor muscle. The morphology of the system is discussed in relation to the process of sodium ion uptake from the ambient medium and from pro-urine, and to that of regulating blood pressure. In the central nervous system and other organs, neurons and axons not labeled with the DNA probes, but immunoreactive to one or two of the antibodies, were observed. It seems unlikely that these elements are functionally related to the SIS-peptide system.
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  • 65
    ISSN: 1432-0878
    Keywords: Pancreas, endocrine ; Immunocytochemistry ; Muscarinic acetylcholine receptor ; Acetylcholine ; Somatostatin ; Rat (Wistar)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Immunocytochemical application of the antimuscarinic acetylcholine receptor antibody M35 to pancreas tissue revealed the target areas for the parasympathetic nervous system. Immunoreactivity in the endocrine pancreas was much higher than that in the exocrine part. Moreover, the endocrine cells at the periphery of the islets of Langerhans displayed the highest level of immunoreactivity. Based on these findings in the mantle of the islets, two types of islets have been distinguished: type-I islets with intensely stained mantle cells, and type-II islets with a much lower concentration of these cells. On average, type-I islets were larger (244.8 μm±6.1 SEM) than type-II islets (121.5 μm±3.8 SEM). M35-immunoreactivity was present on the majority of D cells, which were characterized by their immunoreactivity to somatostatin [of 446 D cells 356 (79.8%) were M35-immunopositive]. However, only a small proportion of the intensely stained mantle cells belonged to the D cell population. Therefore, it is concluded that the majority of the intensely stained mantle cells represent glucagon-secreting A and/or pancreatic polypeptide-secreting F cells. The intensity of M35-immunoreactivity at the periphery and central core of the islets paralleled the density of cholinergic innervation, suggesting a positive correlation between the intensity of cholinergic transmission and the number of muscarinic acetylcholine receptors at the target structures. The present study further revealed some striking parallels for the muscarinic acetylcholine receptor characteristics between the (endocrine) pancreas and the central nervous system.
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  • 66
    ISSN: 1432-0878
    Keywords: Molluscan insulin-related peptide ; Neuropeptide ; Light green cells ; Differential gene expression ; Immunocytochemistry ; In situ hybridization ; Lymnaea stagnalis (Mollusca)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In the pond snail Lymnaea stagnalis, the growth regulating system consists of (1) about 200 neuroendocrine light green cells, located in four clusters in the cerebral ganglia, and (2) the paired canopy cells, located in the lateral lobes. These cells express genes encoding the molluscan insulin-related peptides (MIPs). Six MIP genes have previously been identified. Four of these (I, II, III and V) are expressed in the light green cells and the canopy cells. The MIP-VI gene is a pseudogene. In the present in situ hybridization study, using oligonucleotide probes specific to the transcripts of MIP-I,-II,-III,-IV, and-V, no signal was obtained with the MIP-IV probe, indicating that gene IV is also a pseudogene. With the other four probes, two types of light green cells were distinguished. Type-A cells express all four MIP genes, whereas type-B cells do not (or only faintly) express the MIP-I gene. Gene III is relatively strongly expressed in type-B cells. Genes II and V are moderately expressed in both cell types. Type-A cells are mainly located in the periphery of the clusters, whereas type-B cells are present in the center. The canopy cell resembles type-A light green cells. The expression levels of the MIP-II and MIP-V genes are low in the canopy cell. The expression pattern of the MIP genes correlates with the staining pattern of the anti-MIP-C antibody, which has been raised to a synthetic C-fragment shared by MIP-I,-II and-V. Type-A cells stain more intensely with the antibody than type-B cells.
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  • 67
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    Cell & tissue research 270 (1992), S. 15-23 
    ISSN: 1432-0878
    Keywords: Allatostatin ; Corpus allatum inhibitors ; Immunocytochemistry ; Brain ; Neuroendocrine complex ; Diploptera punctata (Insecta)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A monoclonal antibody against allatostatin I was used to demonstrate the allatostatin-immunoreactive pathways between the brain and the corpus cardiacum-corpus allatum complex in the adult cockroach Diploptera punctata. The antibody was two to three orders of magnitude more sensitive to allatostatin I than to the other four known members of the allatostatin family. Whole and sectioned brains in which immunoreactivity was localized with horseradish peroxidase-H2O2-diaminobenzidine reaction showed strongly immunoreactive cells in the pars lateralis of the brain with axons leading to and arborizing in the corpus cardiacum and the corpus allatum. Although many neurosecretory cells of the pars intercerebralis project to the corpora allata only, four strongly immunoreactive cells were evident here (two pairs on either side), and these did not project to the corpus cardiacum and corpus allatum but rather terminated within the protocerebrum in areas in which lateral cells also formed arborizations. Immunoreactivity was found in many other cells in the brain, especially in the tritocerebrum.
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  • 68
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    Protoplasma 169 (1992), S. 49-56 
    ISSN: 1615-6102
    Keywords: Lectin ; Plasma membrane ; Protoplast isolation ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary An improved method for the mechanical release of protoplasts from plant tissues is described. The historically-low yield of mechanically-released protoplasts is greatly increased by use of a simple electrically-driven tissue sheer and by optimization of various other steps in the procedure. As counted by light microscopy of a purified preparation, the number of mechanically-released protoplasts obtained is about 6×104 per gram fresh weight of cortical tissue from the primary root of maize (Zea mays L. WF9×Mo 17) seedlings. Nuclear staining of the preparation, however, shows that about half of these protoplasts lack a nucleus and thus are actually subprotoplasts. Comparison of lectin binding to the plasma membranes of mechanically-and enzymatically-released protoplasts shows that both types contain binding sites forRicinus communis agglutinin. Binding sites for peanut (Arachis hypogaea) agglutinin are not naturally present on mechanically-released protoplasts but are generated by exposure to a mixture of Cellulysin and Pectolyase Y-23, the cell wall-degrading enzymes used to prepare enzymatically-released protoplasts.
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  • 69
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    Protoplasma 167 (1992), S. 33-42 
    ISSN: 1615-6102
    Keywords: Daucus carota ; Zea mays ; Vigna radiata ; Helicoidal cell walls ; Polylamellate cell walls ; Rapid-freeze deep-etch
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary This paper reports on preliminary investigations into the structure of cell walls of varying complexity as revealed by the rapidfreeze deep-etch technique. Three cell types from different species were examined in order to compare the three-dimensional arrangement of random, polylamellate and helicoidal walls. Each cell type displayed a distinctive level of organisation with respect to the cellulose microfibrils and the matrix material. In polylamellated walls, the microfibrils within each layer were linked to each other by 16–20 nm long side chains regularly spaced along the length of the microfibril. In helicoidal walls, the shifting of the microfibrils could cleary be seen, yet no recognisable structures were observed which could mediate this movement.
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  • 70
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    Protoplasma 168 (1992), S. 125-135 
    ISSN: 1615-6102
    Keywords: Morphogenesis ; Phagotrophic ; Euglenoids ; Immunocytochemistry ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The disruption and development of the siphon during division ofEntosiphon have been followed by immunofluoresence with both an anti-cement MAb (IIID12) and an anti-tubulin MAb. (IVA10), by nuclear DNA labelling and by electron microscopy of serial section. The disruption of the parental siphon begins at the reservoir level where two new transversely orientated daughter siphons arise. In the degenerating bundles the cement disappears, first liberating the microtubules which then depolymerize. The first structure which surrounds the anterior part of the two young siphons is a loop of 5 microtubules linked to the reservoir membrane. From around this loop a row of perpendicular microtubules sink in the cytosplasm; they will form the primary row of microtubules in the definitive bundles. Inside the loop, reinforced microtubules are seen beneath the membrane, they will generate the future vanes, and also penetrate into the cytosplasm. Amorphous material surrounds the young siphons and may correspond to cement material. The growth of the siphons proceeds as they adopt a central longitudinal position in the cell. The cement material progressively condenses on structures such as the primary row of microtubules. The bundles, the supplementary plaque, and the scaffold. After flagellar partition each of the canals becomes distinct and cytokinesis occurs from the anterior end. These observations indicate that the microtubular loop could be the source of microtubule-organizing centre (MTOC) proteins initiating the assembly of the primary row of microtubules. Bundle microtubules start to assemble at the anterior end and extend backwards. The microtubules of the loop could be linked to roots associated with the basal bodies which double in number before division. The cement later condenses, linking and stabilizing the structures. Microfibrils play an important role in basal body and siphon separation and positioning.
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  • 71
    ISSN: 1615-6102
    Keywords: Cryptophytes ; Chloroplasts ; Light-harvesting complexes ; Phycoerythrin ; Chlorophylla/c 2 ; Immunocytochemistry ; Freeze ; fracture labelling
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Immunocytochemical techniques using colloidal gold as the marker have been used to examine the location of the two light harvesting pigment-protein complexes in cryptophyte chloroplasts. A comparison of post-embedding thin section labelling and freeze fracture labelling has been carried out onRhodomonas salina using polyclonal antibodies to a chlorophylla/c 2 light-harvesting complex, phycoerythrin and the β-subunit of phycoerythrin. The effect of different fixation procedures on the intensity of labelling and ac curacy of antigen location have been examined and the effectiveness of uranyl acetate and tannic acid in improving both the preservation of thylakoid structure and labelling density of phycoerythrin has been demonstrated. Freeze fracture labelling gives better spatial res olution of the different antigens than post-embedding labelling, as well as better definition of thylakoid membranes. It confirms the location of phycoerythrin in the thylakoid lumen and the location of the chlorophylla/c 2 LHC in both appressed and unappressed thylakoid membranes.
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  • 72
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    Protoplasma 171 (1992), S. 123-133 
    ISSN: 1615-6102
    Keywords: Endosperm ; Floury-2 ; Immunocytochemistry ; Protein bodies ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The seed storage proteins of maize (Zea mays L.) are synthesized during endosperm development on membrane-bound polyribosomes. These proteins, collectively called zeins, are translocated into the lumen of the rough endoplasmic reticulum, where they assemble into protein bodies. Protein body formation in normal genotypes occurs via an ordered deposition of the various types of zeins, and leads to the formation of spherical structures with a diameter of about 1 μm. These structures consist of a central core that contains predominantly α-zein; this central region is surrounded by a peripheral layer of β- and γ-zeins, and the entire structure is bounded by rough endoplasmic reticulum. In the endosperm mutant floury-2 the levels of all classes of zeins are reduced; these kernels exhibit an opaque phenotype instead of the vitreous phenotype observed in normal genotypes. In contrast to the discrete, spherical protein bodies which are formed in normal maize endosperm, the protein bodies within floury-2 endosperm are irregular and the zeins are disorganized; patches of β- and γ-zeins occur within irregularly lobed clusters of α-zein within the lumen of the rough endoplasmic reticulum. The implications of this aberrant distribution are discussed, both with respect to protein body development and kernel characteristics.
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  • 73
    ISSN: 1615-6102
    Keywords: Fucus ; Light-harvesting complex ; Photosystem I complex ; Thylakoids ; Immunocytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The repartition of light-harvesting complex (LHC) and photosystem I (PS I) complex has been examined in isolated plastids ofFucus serratus by immunocytochemical labelling. LHC is distributed equally all along the length of thylakoid membranes, without any special repartition in the appressed membranes of the three associated thylakoids ofFucus. PS I is present on all the thylakoid membranes, but the external membranes of the three associated thylakoids are largely enriched relatively to the inner ones. This specific repartition of PSI on non-appressed membranes can be compared to the localization of PSI on stroma thylakoid membranes of higher plants and green algae. Consequently, although they share some common features with those of higher plants and green algae, the appressions of thylakoids in brown algae has neither the same structure nor the same functional role as typical grana stacked membranes in the repartition of the harvested energy.
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  • 74
    ISSN: 1615-6102
    Keywords: Endosperm ; Zea mays ; Immunolocalization ; Rough endoplasmic reticulum ; Binding protein ; Protein bodies
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary A maize 75 kDa protein recently has been identified as a plant homolog of the mammalian binding protein (BiP). To better understand the function of BiP in protein body formation in maize endosperm, immunomicroscopy studies were conducted on three maize endosperm mutants, floury-2, Mucronate, and Defective endosperm-B 30, in which the level of BiP is highly elevated. Our results showed that protein body morphology in all three mutants was altered. In addition, BiP was localized in both the ER and peripheral regions of the abnormal protein bodies. The degree to which protein body morphology differed from normal was positively correlated with increased amounts of BiP. In addition, the accumulation of BiP in abnormal protein bodies increased with protein body maturation. In the three endosperm mutants, the arrangement of zeins within protein bodies had been perturbed, yet none of the specific zein subclasses exhibited the staining pattern found for BiP. The association of BiP with abnormal packaging of proteins in protein bodies may reflect a biological function to mediate protein folding and assembly in maize endosperm.
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  • 75
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    Molecular genetics and genomics 234 (1992), S. 353-360 
    ISSN: 1617-4623
    Keywords: Zea mays ; Somatic instability ; Bronze-2 ; Genomic shock ; Pollen
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary After epigenetic loss of Mutator activity, the family of Mu elements in Zea mays becomes immobile and highly methylated; in addition, Mu9, the presumptive autonomous regulatory element, is transcriptionally silent and its copy number decreases in successive crosses to non-Mutator lines. Spontaneous reactivation, scored as restoration of somatic instability of potentially mutable alleles of Bronze-2, of such cryptic Mutator lines is rare, occurring with a frequency of about 10−4. Irradiation of pollen with 254 nm ultraviolet light increases reactivation rate in the progeny kernels by up to 40-fold. Accompanying reactivation, the copy number of Mu9 elements increased, two-fold in one line and 20 to 40-fold in a second line. Reactivation may involve direct DNA damage or immediate physiological stress in the treated pollen.
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  • 76
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    Molecular genetics and genomics 233 (1992), S. 379-387 
    ISSN: 1617-4623
    Keywords: Bz2 gene ; Transcriptional regulation ; Anthocyanin pathway ; Transient assay ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The putative maize transcription factor genes R and C1 are required for expression of reporter genes with promoters from the Bz1 and A1 genes, which encode enzymes required for anthocyanin biosynthesis in maize. Bz2 is another anthocyanin biosynthetic gene; we show that expression of a reporter gene from the Bz2 promoter also requires R and C1 when the fusion construct is introduced into maize kernels by particle gun bombardment. When electroporated into maize protoplasts from a suspension cell line not synthesizing anthocyanins, reporter genes with Bz2, Bz1, and A1 promoters are expressed only when both R and C1 expression plasmids are co-electroporated. Electroporation of R and C1 expression plasmids also induces the endogenous genes required for anthocyanin synthesis, resulting in pink protoplasts within 24 h. RNase protection analysis demonstrates that accumulation of mRNA from the endogenous Bzl and Bz2 genes absolutely requires introduced R and C1. In time-course experiments there is a delay of 3–6 h before the Bz2 promoter is activated, supporting the proposed role for R- and C1-encoded proteins in transcriptional control. An excess of R relative to C1 suppresses expression of A1, Bz1, and Bz2 promoters, suggesting an interaction between the R and C1 proteins.
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  • 77
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    Molecular genetics and genomics 233 (1992), S. 388-394 
    ISSN: 1617-4623
    Keywords: Viral vector ; Transposable element ; Zea mays ; Agroinfection
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary We have previously shown that the maize transposable element Ds1 introduced into maize plants by agroinfection can be excised from the genome of geminivirus maize streak virus (MSV). Excision depended strictly on the presence of an active Ac element in the plants. In this study, the excision products or “footprints” left in the MSV genome after Ds1 excision were extensively characterized and the effects of flanking sequences on Ds1 excision were analysed. Most types of footprints obtained were comparable to those described for Ds1 excision in the maize genome, and could be explained by the models proposed for excision of plant transposable elements. In two revertants, however, some terminal sequences of the Ds1 element were found to have been left behind at the excision site. The finding of this novel type of Ds1 footprint indicated that gene conversion events occurred during and/or after Ds1 excision from the MSV genome. A partial deletion of one copy of the 8 by duplications flanking the Ds1 element had no effect on the frequency or on the types of footprints of Ds1 excision from the MSV genome. Thus, the duplicated 8 by sequences flanking the transposable element are not involved in Ds1 excision. These results, as well as a statistical analysis of the modifications of the bases flanking the Ds1 element after excision, are discussed in terms of excision models.
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  • 78
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    Molecular genetics and genomics 231 (1992), S. 369-374 
    ISSN: 1617-4623
    Keywords: Zea mays ; Transcription ; Transformation ; Endosperm ; Tissue culture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary A 43 by fragment containing the — 300 region upstream control element common to the endosperm expressed zein genes of Zea mays L. has been analyzed by in vivo and in vitro techniques. Transient transformation studies with protoplasts from a maize endosperm culture indicate that the element positively affects CaMV 35S promoter-driven gene expression, and that this effect is both orientation- and position-dependent. Band-shift and Southwestern blotting experiments demonstrate that the element is specifically bound by different sets of DNA-binding proteins from seedling and endosperm nuclei. A 2 by substitution within the most conserved region of the element both reduces the stimulatory effect on transcription and alters the binding of nuclear proteins from both tissues.
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  • 79
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    Molecular genetics and genomics 233 (1992), S. 269-277 
    ISSN: 1617-4623
    Keywords: Zea mays ; Bz2 locus ; Natural antisense transcripts ; Transposable elements ; Gene family
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Analysis of the transcription pattern of theBz2 locus revealed that overlapping transcripts are derived from opposite DNA strands. The most abundant transcript (sense transcript) has an open reading frame coding for a protein of 241 amino acids, whilst in the antisense orientation no open reading frame has been detected; the antisense transcripts are detected only in those tissues that show high levels of sense transcript. Particle gun experiments indicate that the sense transcript is sufficient to provide theBz2 function. The promoter driving the sense transcript contains the elements usually found in front of eukaryotic genes. In addition an element with similarity to theC1 andR binding sites identified in theBz1 promoter is found. Further upstream in the promoter region a transposon-like insertion has been identified. This element has features similar to members of theAc/Ds transposable element family. The putativeBz2 protein shows similarity to various other plant proteins and to anEscherichia coli protein. All related proteins have in common the fact that they are involved in stress responses.
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  • 80
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    Plant and soil 144 (1992), S. 199-205 
    ISSN: 1573-5036
    Keywords: acid phosphatase ; ectoenzymes ; naphthyl phosphate ; Picea abies ; rhizosphere ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract For in vivo demonstration of acid phosphatase activity in the rhizosphere of soil-grown plants filter papers were treated with a mixture of 1-naphthyl phosphate as substrate and the diazonium salt Fast Red TR as an indicator. After enzymatic hydrolysis, 1-naphthol forms a red complex with Fast Red TR. This method was applied to 8-day old maize plants and 3-year old Norway spruce plants growing in rhizoboxes in soil under non-sterile conditions. The treated filter paper is placed at the surface of roots and soil and acid phosphatase activity is visualized as a red-coloured ‘root print’ on the filter paper. The method can be used as a qualitative analysis of acid phosphatase in the rhizosphere. It also allows a rough estimate of phosphatase activity in different root zones.
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  • 81
    ISSN: 1573-5060
    Keywords: cold tolerance ; correlated responses ; germination ; kernel type ; kernel weight ; recurrent selection ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Four cycles of divergent full-sib recurrent selection for the ability to germinate at low temperature were conducted in a maize (Zea mays L.) F2 population. The selection criterion was the high (H) or the low (L) value in algebraic terms of the difference (DG) between germination percentage at 9.5°C (G9.5) detected 19 days after sowing and germination percentage at 25°C (G 25) seven days after sowing; both traits were evaluated in a controlled environment (germinator). Direct and correlated responses estimated during the course of selection were in accordance with those evaluated at the end. Selection for H led to populations with higher DG values, while the reverse was noted for L; differences between H and L populations increased in successive selection cycles, though divergence tended to level off. Selection for H also resulted in higher G 9.5 (day 19), shorter germination time and more flinty kernels, while selection for L led to responses in the opposite direction as well as to a lower G 9.5 detected 37 days after sowing (i.e. at the end of germination). In contrast, responses were negligible for G 25 and varied erratically from one cycle to another for kernel weight.
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    Plant cell, tissue and organ culture 28 (1992), S. 129-137 
    ISSN: 1573-5044
    Keywords: cms-T ; in vitro selection ; methomyl resistance ; mitochondrial mutation ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Several factors affecting the success of selection in plant populations were examined for their relevance to in vitro selection. Three in vitro selection schemes and two growth assessment procedures were evaluated for effectiveness in selecting for a mitochondrial trait in maize: resistance to the insecticidal compound methomyl. Regenerable maize callus was derived from immature embryos of the three-way hybrid P39/IL766A2 x W182BN containing Texas male sterile cytoplasm (cms-T). Either low, gradually increasing, or high selection pressures were used to grow callus over a period of 3–5 months. There was no significant difference in recovery of resistant plants using these 3 methods. Growth of callus on medium containing methomyl was assessed by increase in fresh weight during the final month of selection or by increase in number of callus pieces over the course of selection. These quantitative measures of growth were unreliable indicators for gain in resistance within the callus population. A procedure for recovery of methomyl resistant and male-fertile cms-T plants is suggested.
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  • 83
    ISSN: 1573-5044
    Keywords: cell cycle ; DNA content ; embryogenic competence ; flow cytometry ; mitotic activity ; somatic embryogenesis ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Embryogenic competence of maize (Zea mays L.) leaf tissues was studied with regard to leaf age, distance from leaf base, mitotic activity, 2C nuclear DNA content, and the distribution of cells within the cell cycle. The highest embryogenic competence was observed in the first segment of the second innermost leaf. In a succession of 8 mm segments from the leaf base, the frequency of cells in the G0/G1 phase of the cell cycle and mitotic activity decreased with leaf age and with the distance from leaf base. No significant differences in 2C nuclear DNA content were found for leaf segments of different age and position. The mean 2C nuclear DNA content was 5.74 pg. The results suggested that the loss of embryogenic competence in mature maize leaf tissues is not related to changes in nuclear DNA content, and that the competence is not simply related to a certain distribution of cells within the cell cycle or to a certain level of mitotic activity.
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    Journal of chemical ecology 18 (1992), S. 1981-1990 
    ISSN: 1573-1561
    Keywords: Allelopathy ; ferulic acid ; amylase ; maltase ; invertase ; acid protease ; acid phosphatase ; Zea mays ; growth ; root ; shoot
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Ferulic acid was tested for its effect on the growth of root and shoot, fresh and dry weights, and hydrolytic enzyme activities of germinating maize seeds. The results showed that root growth was inhibited more than shoot growth. A significant reduction in the activities of hydrolytic enzymes was also observed, which reflects a mechanism of action for the natural growth inhibitors, which may include other phenolic compounds.
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  • 85
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    Journal of chemical ecology 18 (1992), S. 897-905 
    ISSN: 1573-1561
    Keywords: Pollen ; corn ; Zea mays ; teosinte ; Zea mexicana ; allelopathy ; phenylacetic acid ; phytotoxicity ; Amaranthus leucocarpus ; Echinochloa crusgalli
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Phenylacetic acid (PAA), one of the phytotoxic compounds in corn (Zea mays) pollen, was identified by GC-MS and by direct comparison with a pure commercial sample of PAA. Bioassays were carried out by testing whole pollen, methylene chloride extract of the pollen, and pure PAA on germination and radical growth ofAmaranthus leucocarpus andEchinochloa crusgalli. The effect of corn pollen was compared with that ofZea mexicana (Teosinte), one of the wild relatives of cultivated maize.
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  • 86
    ISSN: 1573-5060
    Keywords: coancestry coefficient ; genetic similarity ; maize ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary In this study, 31 elite inbred lines of maize (Zea mays L.) were analyzed with 149 clone-enzyme combinations for their respective RFLP profiles. Objectives were (1) to determine the utility of RFLPs for estimation of genetic similarties among 16 inbred lines from the Iowa Stiff Stalk Synthetic (BSSS) and among 15 inbred lines from the Lancaster Sure Crop (LSC) heterotic groups and (2) to compare genetic similarities based on molecular markers with those based on pedigree information. Coefficients of genetic similarity (GS) and coancestry (f) between pairs of lines from the same heterotic group were calculated from RFLP and pedigree data, respectively. For lines from the BSSS heterotic group, cluster analyses based on RFLP and pedigree data revealed similar associations. GS and f values were closely correlated (r=0.70) for related BSSS lines. For lines from the LSC heterotic group, considerable discrepancies existed between the GS and f values, especially for those pairs involving inbreds Va22 and Lo924. Effect of selection and/or erroneous pedigree records are discussed as possible explanations for the low correlation of GS and f values (r=0.07) for related LSC lines. RFLPs seem useful for investigation of relationships among maize inbreds, verification of pedigree records, and quantification of the degree of relatedness.
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  • 87
    ISSN: 1573-5060
    Keywords: androgenesis ; in vitro culture ; maize ; microspores ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The capacity of the maize genotype 4c1 to regenerate microcalli and embryos from cultured microspores has been examined by comparing various cold pretreatments and culture media, using microspores and pollen at different stages of development. Viability of cultured cells was tested with FDA and their development was traced with light and fluorescence microscopy using DAPI as a nuclear dye. It was found that a pre-incubation of dissected flowers floating in a liquid nutrient medium at 8°C during 10–14 days was most successful for the induction of cell division. Among the developmental stages tested only the microspores appeared to regenerate. Subculture at 25°C in the same liquid medium, supplemented with 0.1 mg/l TIBA, gave highest rates of microspore division, i.e. up to 70% at 4 to 6 days of culture. All pathways described earlier for maize androgenic embryogenesis were observed within the 4c1 genotype. Symmetric divisions occurred in cultured microspores but most frequently asymmetric divisions lead to the formation of microcalli within 12 days of culture. In at least 60% of all dividing microspores cells were derived from the generative nucleus. Microcalli further developed either into loose or compact calli. Compact calli formed embryo-like structures.
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  • 88
    ISSN: 1573-5060
    Keywords: population improvement ; maize ; Zea mays ; honeycumb selection ; adaptability ; stability ; yield
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary This study was undertaken to investigate the implications of genotype x soil texture interaction on response to selection in maize. Mass honeycomb selection for yield was applied for 11 cycles from the F2 of the single cross maize hybrid F68×NE2 in a field B with silty-clay-loam soil texture. Response to selection compared to the original single cross hybrid was estimated both in absence of competition and under solid stand in the selection field B and in a nearby field A differing in soil texture (clay-loam). A strong crossover type of interaction occurred both under solid stand and in the absence of competition in the two tests the improved population outyielded the hybrid in field B in the two densities, but lagged behing the hybrid in field A. The results suggest that interaction between genotype and soil texture might affect efficiency of selection detrimentally unless provision is taken for parallel selection early in the crop improvement program in fields differing in soil texture.
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  • 89
    ISSN: 1573-5060
    Keywords: doubled haploid ; genetic marker ; wheat ; wheat x maize crosses ; Triticum aestivum ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Wheat doubled haploid (DH) lines were produced from the F1 hybrid, Fukudo-komugi x Oligo Culm, through intergeneric crosses between wheat and maize. F2 plants and 203 DH lines were analyzed for the segregation of the eight genetic markers, namely, grain proteins, grain esterases, GA-insensitivity and glume traits. The segregation in the F2 plants fitted to the expected ratios. No deviation was observed among the DH lines, either, except for the glume pubescence. The result indicates the absence of correlation between the markers investigated and the efficiency of embryo formation in the DH lines.
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  • 90
    ISSN: 1573-5060
    Keywords: forage maize ; Zea mays ; breeding ; nutritive value ; cell-wall digestibility ; stalk quality
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The current study deals with genetic improvement of the nutritive value of forage maize. In separate field trials, maize inbred lines without the brown midrib trait and derived hybrids were evaluated for stalk quality as well as some other agronomic traits. The aim was to relate the performance of lines and hybrids. Quality traits studied were the contents of ash and cell walls expressed as percentage of dry matter and the digestibilities of organic matter and cell walls (stalk-dv% and stalk-dcw%, respectively). The performance of hybrids was established in a trial at two locations with three replicates per location and the performance of lines at one location in an unreplicated trial. The range for stalk-dcw% was about 10 percentage units between hybrids and 15 percentage units between inbred lines. Stalk-dcw% had of all quality traits of hybrids the highest broad-sense heritability (h 2=0.74), and determined about 80% of the variation in stalk-dv%. The only stalk quality trait where a significant correlation was found between the mean hybrid performance and the corresponding midparent value was stalk-dcw% (r=0.70, P〈0.01). In conclusion, stalk-dcw% proved to be the only stalk quality trait worth evaluating at the inbred line level in a breeding programme aimed at producing commercial hybrid varieties of forage maize.
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  • 91
    ISSN: 1573-5060
    Keywords: cluster analysis ; principal component analysis ; accession ; landraces ; Zea mays ; maize ; dendrogram ; variation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Two multivariate techniques were used to characterize 30 maize accessions collected from three ecological zones of Bendel State, Nigeria. Differentiation of the 30 accessions into five distinct groups was achieved with the unweighted variable group method of the average linkage cluster analysis of 34 agronomic characters. Four of the taxonomic groups contained at least three accessions each, while a fifth group contained only one. The single accession contained in the fifth group was characterised by very early maturity, deeply pigmented leaves and ear husks and short statured plants. Clustering of the accessions into different phenetic groups followed substantially along geographical and traditionally trading routes. A few cases of overlapping of accessions from different geographical locations were obtained. Principal component analysis revealed that days to 50% tasseling and silking, number of nodes/plant, ear length, ear weight, leaf width, and kernel colour were the principal discriminatory characters that differentiated the accessions. Sixty-four percent of the total variation among the 34 characters were accounted for by the first five principal components while the first and second components accounted for 26 and 14 respectively.
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  • 92
    ISSN: 1573-5087
    Keywords: Mitochondria ; respiration ; seed ageing ; seed storage ; temperature ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract This paper reports on a study of mitochondrial activity in etiolated shoots of freshly harvested and moderately aged kernels of maize. Activity was investigated after incubation at a favourable temperature (25°C), sub-optimal temperature (13°C) and after a heat shock (46°C for 2h). Although impaired mitochondrial activity in shoots from moderately aged maize kernels was not detected at 25°C, deficiencies became evident under low temperature stress (13°C). State 3 oxygen uptake, cyanide-insensitive oxygen uptake and cytochrome oxidase activity were lower in mitochondria from these shoots at 13°C than in mitochondria from shoots of freshly harvested kernels at this temperature. After a heat shock, cyanide-insensitive oxygen uptake was higher, and cytochrome oxidase activity lower, in shoots of aged kernels than in shoots of fresh kernels. No significant differences in ADP: O ratio or succinate dehydrogenase activity occurred between mitochondria from shoots of the two seed lots in any of the temperature treatments.
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  • 93
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    Journal of chemical ecology 18 (1992), S. 931-944 
    ISSN: 1573-1561
    Keywords: Diabrotica virgifera virgifera ; 6-methoxy-2-benzoxazolinone ; hydroxamic acids ; semiochemical ; attractants ; western corn rootworm ; host location ; Coleoptera ; Chrysomelidae ; Zea mays ; kairomone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract A bioassay-driven sequential fractionation scheme was used to isolate all portions of a crude dichloromethane corn seedling extract behaviorally active to larvae of the western corn rootworm,Diabrotica virgifera virgifera LeConte. 6-Methoxy-2-benzoxazolinone (MBOA) was identified as one of the most important components of an attractive crude corn extract. MBOA was found on or in the intact root tissues by injecting an extract of undamaged roots onto an HPLC immediately after extraction. MBOA was demonstrated to be volatile and functions as a semiochemical in conjunction with carbon dioxide in host location by western corn rootworm larvae, which are oligophagous on the roots of maize and several other species of grasses. Because MBOA occurs almost exclusively in maize and other grasses, it offers a simple way for the larvae to distinguish possible hosts from non-hosts. MBOA has previously been reported as a chemical defense against other insect species. This is the first report in grasses of a secondary compound that is toxic or a deterrent to nonadapted insect herbivores but that is used as a semiochemical in host location by a specialist insect species.
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  • 94
    ISSN: 1573-8248
    Keywords: Beauveria bassiana ; Ostrinia nubilalis ; endophytic relationship ; biological control ; insect pathology ; Zea mays ; Beauveria bassiana ; Ostrinia nubilalis ; lutte biologique ; relation endophyte ; pathologie de l'insecte ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Description / Table of Contents: Résumé Le champignon entomopathogène,Beauveria bassiana (Balsamo) Vuillemin a été épandu sur maïs, au stade cornet (V7) par application foliaire d'une formulation granulée de grits de maïs contenant des conidies ou par injection d'une suspension de conidies. Toutes les plantes ont été infestées à l'aide de larves de la Pyrale du maïs,Ostrinia nubilalis, au stade V7 (cornet), V12 (fin de stade cornet), ou V17 (apparition de la panicule). Les plantes infestées au stade cornet et à la fin du stade cornet ont eu significativement plus de chenilles de Pyrale en train de miner que les plantes infestées au stade début de panicule mâle. Le pourcentage de plantes infestées parB. bassiana n'était pas significativement différent entre ces 3 stades phénologiques. Au fur et à mesure que les plantes se développaient,B. bassiana était isolé de différentes parties de la plante, la moelle étant plus souvent infestée que les ligules. Les applications foliaires deB. bassiana ont entraîné la destruction immédiate de la pyrale chez les plantes infestées au stade cornet. La baisse de l'efficacité deB. bassiana aux stades intermédiaires par comparaison avec son efficacité au moment de la récolte est discutée.
    Notes: Abstract The entomopathogenic fungus,Beauveria bassiana (Balsamo) Vuillemin, was applied to whorl-stage (V7) corn,Zea mays L., by foliar application of a granular formulation of corn grits containing conidia or by injection of a conidial suspension. All plants were infested with European corn borer larvae,Ostrinia nubilalis (Hübner), at the V7 (whorl), V12 (late-whorl), or V17 (pretassel) stage of plant development. Plants infested at whorl and late-whorl stages had significantly more European corn borer tunneling than did plants infested at the pretassel stage. The percentage of plants colonized byB. bassiana did not differ significantly among the whorl, late-whorl, and pretassel stages. As the plants matured,B. bassiana was isolated from different plant areas, with the pith more frequently colonized than the leaf collars. Foliar application ofB. bassiana provided immediate suppression ofO. nubilalis in those plants infested at whorl stage. The reduced efficacy ofB. bassiana at the intermediate plant stages relative to efficacy at harvest is discussed.
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