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  • 1
    Electronic Resource
    Electronic Resource
    An Automated Perifusion System for the Study of Rat Spermatogenesis in Vitro (1987)
    Oxford, UK : Blackwell Publishing Ltd
    Annals of the New York Academy of Sciences 513 (1987), S. 0 
    Details
    ISSN: 1749-6632
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Natural Sciences in General
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1749-6632.1987.tb25005.x
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  • 2
    Electronic Resource
    Electronic Resource
    Electron microscopy of t -allele synaptonemal complexes discloses no inversions (1982)
    [s.l.] : Nature Publishing Group
    Nature 299 (1982), S. 752-754 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] The cross-over suppression of t haplotypes masks the true genetic nature of the region. It has previously been convenient to consider the t alleles as point mutations mapping near T. Lyon's thorough analysis of this chromosomal region using rare cross-overs established the non-allelism of several ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/299752a0
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  • 3
    Electronic Resource
    Electronic Resource
    Nucleolar RNA synthesis of meiotic prophase spermatocytes in the human testis (1975)
    Springer
    Chromosoma 53 (1975), S. 141-151 
    Details
    ISSN: 1432-0886
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Human meiotic prophase spermatocyte nuclei were studied by electron microscope autoradiography after a 3 hours 3H-uridine labeling pulse, followed by postincubation in non-radioactive medium. In autosomes, 3H-uridine nucleolar labeling reaches a peak during early-middle zygotene prior to the peak labeling of chromosomal RNA species at middle pachytene. Transcription activities of sex chromosomes are inconspicuous when compared with that of autosomes. An increasing condensation of nucleolar-associated chromatin in acrocentric bivalents contributes to the formation of basal knobs in human pachytene spermatocytes. Upon completion of knob formation, nucleolar components segregate and the uptake of 3H-uridine decreases. These findings suggest that the template capability of ribosomal DNA cistrons, located next to the basal knob region, is largely associated with a dispersed state of chromatin whereas increased chromatin condensation is correlated with a restriction of ribosomal RNA transcription.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00333042
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  • 4
    Electronic Resource
    Electronic Resource
    Characterization of cyclic AMP-binding proteins in rat Sertoli cells using a photoaffinity ligand (1984)
    Springer
    Molecular and cellular biochemistry 60 (1984), S. 147-157 
    Details
    ISSN: 1573-4919
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Summary Protein-bound cyclic AMP (cAMP) levels in cultured rat Sertoli cells have been determined after exposure to follicle-stimulating hormone (FSH) and agents which elevate intracellular cAMP or mimic cAMP action. Changes in the content of protein-bound cAMP were correlated with changes in receptor availability determined by measuring [3H] cAMP binding. Using the photoaffinity analog of cAMP, 8-N3 [32P] cAMP, two major cAMP-binding proteins in Sertoli cell cytosol, with molecular weights of 47 000 and 53 000 daltons, were identified as regulatory subunits of type I and type II cAMP-dependent protein kinases, respectively. Densitometric analysis of autoradiograms demonstrated differential activation of the two isozymes in response to treatment with FSH and other agents. Results of this study demonstrate the value of measuring changes in protein-bound cAMP and the utility of the photoaffinity labeling technique in correlating hormone-dependent processes in which activation of cAMP-dependent protein kinase occurs.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00222485
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  • 5
    Electronic Resource
    Electronic Resource
    Antibodies to rat sperm tail polypeptides recognize Sertoli cell secretory proteins (1989)
    Springer
    Molecular and cellular biochemistry 85 (1989), S. 171-179 
    Details
    ISSN: 1573-4919
    Keywords: outer dense fibers ; keratin-like fibers ; immunogold electron microscopy ; spermatogenesis ; spermiogenesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract We have previously reported that (a) polyclonal antisera raised against rat Sertoli cell secretory protein S70 and S45-S35 heterodimeric protein recognize outer dense fiber polypeptides from rat sperm tail, and (b) protein S70 is antigenically related to polypeptides S45 and S35, the disulfide-linked components of the heterodimeric protein. We now report that polyclonal antisera generated against three different outer dense fiber polypeptides recognize (a) the putative antigen of the sperm tail and (b) Sertoli cell secretory protein S70 and its antigenically-related polypeptides. Immunogold electron microscopy shows that outer dense fibers of epididymal sperm crossreact with anti-S70 serum as well as with an antiserum raised against the polypeptide D complex of extracted outer dense fibers. Electron microscopy demonstrates that outer dense fibers consist of filamentous, coil-coiled units aligned side-by-side with each other. Results of this study strengthen the antigenic homology between Sertoli cell secretory proteins and outer dense fiber polypeptides of the sperm tail.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00577112
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  • 6
    Electronic Resource
    Electronic Resource
    Rat Sertoli-spermatogenic cell co-cultures established on collagen-glycosaminoglycan crosslinked copolymers (1992)
    Springer
    Methods in cell science 14 (1992), S. 265-269 
    Details
    ISSN: 1573-0603
    Keywords: glycosaminoglycans ; collagen ; Sertoli cell ; spermatocytes ; spermatogenesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The role of permeable substrates on the proliferation and differentiation of rat spermatogenic cells in co-culture with Sertoli cells was evaluated. Co-cultures were prepared on substrate discs consisting of a thin, stable analog of extracellular matrix attached to a polyester mesh to facilitate handling. Substrate discs were used alone or mounted within a polysulfone reusable holder. Substrates included collagen type I alone or crosslinked with the glycosaminoglycans (GAG) chondroitin-6-sulfate (8%) or heparin (5%). Chemical crosslinking immobilizes collagen and GAG components, preserves the native triple-helical configuration of collagen type I, and renders the copolymer more resistant to degradation by cellular enzymes. Cell attachment and growth properties of Sertoli and spermatogenic cells on these substrates were compared with another permeable substrate (HATF, a mixture of cellulose esters) uncoated or coated with Matrigel (extracellular matrix material derived from EHS tumors) and with the more conventional nonpermeable glass or plastic substrates. We have found that Sertoli-spermatogenic cell co-cultures prepared from pubertal rats readily attach to collagen or collagen-GAG substrate discs as well as to HATF. However, the optical transparency of collagen or collagen-GAG, as compared to the opaque HATF substrate, facilitates monitoring cell attachment and growth by phase contrast microscopy. Substrate discs processed for light and electron microscopy using standard procedures demonstrate the organization of a structurally polarized epithelial layer with basally located Sertoli cells and spermatogenic cells associated by lateral and apical Sertoli cell surfaces. The permeable nature of the collagen-GAG substrate, its optical transparency, and the formation of an electrical-resistant, polarized Sertoli-spermatogenic cell epithelial layer opens new in vitro experimental possibilities for testing agents that may favor or disrupt the spermatogenic process.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01409020
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  • 7
    Electronic Resource
    Electronic Resource
    Antigenic homology between rat sperm tail polypeptides and Sertoli cell secretory proteins (1988)
    Springer
    Molecular and cellular biochemistry 81 (1988), S. 165-176 
    Details
    ISSN: 1573-4919
    Keywords: sperm tail ; immunofluorescence ; Sertoli cell secretory proteins ; antigenic homology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract A high performance liquid chromatographic procedure has been used for the purification of rat Sertoli cell secretory protein S70 and S45-535 heterodimeric protein to determine their role during spermatogenesis. These two proteins display binding affinity for each other and appear antigenically related. We have observed that: 1. S70 and S45-S35 heterodimeric protein coelute during purification, 2. polyclonal antiserum raised against protein S70 recognizes common antigenic determinants in polypeptides S45 and S35, the disulfide-linked components of the heterodimeric protein, and 3. a monoclonal antibody that recognizes polypeptide S35 but does not crossreact with either protein S70 or polypeptide S45, immunoprecipitates the S70/S45-S35 heterodimeric protein complex. In immunofluorescent experiments, antisera raised against protein S70 and polypeptide components of S45-S35 heterodimeric protein immunoreact with two major sperm intracellular structures: the acrosome and periaxonemal outer dense fibers of sperm tail. Immunoreactivity was not detected on the sperm plasma membrane surface of unfixed, living sperm. Outer dense fibers extracted from sperm tails by a combined treatment with cetylthrimethylammonium bromide and 2-mercaptoethanol, yielded a characteristic polypeptide pattern. In immunoblotting experiments, sperm tail polypeptides were recognized by polyclonal antisera raised against Sertoli cell secretory proteins. We conclude that Sertoli cell secretory proteins S70 and S45-S35 heterodimeric protein are antigenically related to each other and to keratin-like polypeptides from sperm tail.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00219319
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  • 8
    Electronic Resource
    Electronic Resource
    The ultrastructure of the nuclei and the behaviour of the sex chromosomes of human spermatogonia (1968)
    Springer
    Cell & tissue research 91 (1968), S. 75-89 
    Details
    ISSN: 1432-0878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The nuclear structure of human spermatogonia has been studied with electron microscopical and histochemical methods. Type B spermatogonia have chromatin clumps without any special ultrastructure and several nucleoli. Five different types of nuclear bodies, and besides, a nuclear vacuole, have been observed in type A spermatogonia. Type I bodies are typical nucleoli consisting of three regions: amorphous, fibrillar and granular. Type II, III and V are considered to be atypical nucleoli. Type IV bodies are small chromatin condensations. Type I bodies are the only ones in which RNA was demonstrated by light histochemical techniques and no PAS positive material was found inside the nuclei. The absence of any special ultrastructure in the chromatin from spermatogonia, and the small mass of the chromatin condensations, show that the human X chromosome and perhaps the Y chromosome are not heteropycnotic in the interphasic nuclei of human spermatogonia.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00336985
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  • 9
    Electronic Resource
    Electronic Resource
    Galactosyl receptor in human testis and sperm is antigenically related to the minor C-type (Ca2+-dependent) lectin variant of human and rat liver (1995)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 40 (1995), S. 460-466 
    Details
    ISSN: 1040-452X
    Keywords: Spermatogenesis ; Sperm-zona pellucida binding ; Transmembrane animal lectin proteins ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Galactosyl receptor, a cell surface Ca2+-dependent lectin with binding affinity for galactose, was evaluated by immunoblotting, immunoprecipitation, Northern blotting, and immunocytochemistry in human liver, testis, and sperm. Polyclonal antisera raised against the minor asialoglycoprotein receptor variant of rat hepatocytes (designated rat hepatic lectin-2/3, RHL-2/3), and its human liver-equivalent (designated H2), recognize native galactosyl receptor in the testis and sperm in immunoblotting, immunoprecipitation, and immunocytochemical experiments. An equivalent to the major hepatocyte asialoglycoprotein receptor variant (rat RHL-1 and human H1) was not detected. Human testis and sperm galactosyl receptor was resolved, after immunoprecipitation and immunoblotting, as a single protein component of molecular mass 50 kD. The single protein component in human testis and sperm contrasted with the doublet nature of rat testis and sperm galactosyl receptor, consisting of two components of molecular masses of 54 and 49 kD. Northern blotting experiments using radiolabeled H1 and H2 cDNA probes confirmed the presence of H2 mRNA and the lack of H1 mRNA in the human testis. Immunocytochemical studies detected specific antigenic sites on the entire surfaces of spermatogenic cells. However, immunoreactivity in epididymal and ejaculated sperm was confined to head surfaces overlying the acrosome. Results from these studies, and from previous studies in the rat, suggest that the testis/sperm galactosyl receptor is a C-type Ca2+-dependent lectin with possible roles in cell-cell interaction during spermatogenesis and sperm-zona pellucida binding at fertilization. © 1995 Wiley-Liss, Inc.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1080400410
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  • 10
    Electronic Resource
    Electronic Resource
    Rat sertoli and spermatogenic cells express a similar gene, and its product is antigenically related to an outer dense fiber-associated protein (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 33 (1992), S. 363-372 
    Details
    ISSN: 1040-452X
    Keywords: Sperm tail ; Testis ; Sertoli cells ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: We have previously reported that a heterodimeric protein secreted by rat Sertoli cells is antigenically related to a protein associated with outer dense fibers of the sperm tail. Therefore, we have explored the possibility that Sertoli and spermatogenic cells express a similar gene encoding a homologous protein. A Sertoli cell heterodimeric protein cDNA probe recognizes specific mRNA in pachytene and round spermatids fractionated by centrifugal elutriation; however, this specific mRNA was less prominent than in cultured Sertoli cells. In agreement with these observations, in situ hybridization experiments show that Sertoli cells are predominantly engaged in active heterodimeric protein mRNA synthesis, while meiotic prophase spermatocytes and spermatids also show significant but less abundant specific mRNA. Immunoblotting experiments demonstrate that, while Sertoli cells synthesize a heterodimeric protein consisting of two disulfidelinked components with molecular masses of 45 and 35 kD, both primary spermatocytes and round spermatids synthesize single 30 kD monomers not associated by disulfide linkage but recognized by antisera to Sertoli cell heterodimeric protein Immunoblotting and immunogold electron microscopic studies show that antisera to Sertoli cell heterodimeric protein recognize a protein associated with outer dense fibers. This immunoreactivity was abolished by a 5-min pronase treatment, without affecting the integrity of outer dense fibers. Results of this study and previous studies demonstrate that both Sertoli and spermatogenic cells express a similar gene and that an antigenically related product encoded by this gene becomes associated with outer dense fibers during their assembly at spermiogenesis. © 1992 Wiley-Liss, Inc.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1080330402
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