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  • 1
    Electronic Resource
    Electronic Resource
    Apoptosis in mouse primordial germ cells: a study by transmission and scanning electron microscope (1994)
    Springer
    Anatomy and embryology 189 (1994), S. 435-440 
    Details
    ISSN: 1432-0568
    Keywords: Apoptosis ; Primordial germ cells ; Mouse embryo ; Gametogenesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract A detailed study of the death in vitro of mouse primordial germ cell (PGCs) by means of transmission and scanning electron microscopy is reported. The results show that after 4–5 h of culture 15–20% PGCs assume the typical morphological features of apoptotic cells, including chromatin condensation in dense masses under the nuclear membrane, compaction of the cytoplasm, crowding of organelles and surface protuberances. Cells then break up into discrete fragments (apoptotic bodies) which eventually degenerate by “secondary necrosis”. It is possible that apoptosis plays a biologically useful role in avoiding uncontrolled PGC proliferation and in eliminating misplaced germ cells whose survivial might be harmful to the animal.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00185438
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  • 2
    Electronic Resource
    Electronic Resource
    Low-affinity nerve growth factor receptor is expressed during testicular morphogenesis and in germ cells at specific stages of spermatogenesis (1994)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 37 (1994), S. 157-166 
    Details
    ISSN: 1040-452X
    Keywords: Neurotrophin receptors ; Testis development ; Spermatogenesis ; Male germ cells ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Nerve growth factor (NGF) is essential for neuronal development and differentiation. Recent reports have shown that its low-affinity receptor (LNGFR) is expressed and developmentally regulated in a broad range of embryonic and adult tissues outside the nervous system, although the functions of the receptor in such tissues remain unknown. Recently, NGF and LNGFR have been detected in adult mouse, rat, and human testis.The results of the present work demonstrate that LNGFR is expressed much before the onset of spermatogenesis in both mouse and rat testis. In situ hybridization shows that the mRNA for LNGFR is expressed in the peritubular cells of the embryonic mouse testis. Immunohistochemical analysis of the rat testis shows LNGFR-expressing cells to be scattered in the intertubular compartment in the embryonic testis, and to become organized in a cellular layer that surrounds myoid cells of the seminiferous tubules during postnatal development. Furthermore, in peripuberal and adult mouse and rat testis we have identified the expression of an abundant and shorter mRNA of 3.2 kb that cross hybridizes to the low-affinity NGF receptor transcript (3.7 kb). This shorter mRNA species, which appears at the beginning of spermatogenesis in the adult, has been identified by in situ hybridization and by Northern blot with RNA isolated from homogeneous populations of meiotic germ cells to be expressed by pachytene spermatocytes and round spermatids. Our results suggest a complex developmental role for LNGFR during testicular morphogenesis and identify the expression, at specific stages of spermatogenesis, of a new germ cell - specific transcript homologous to the receptor RNA. © 1994 Wiiey-Liss, inc.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1080370206
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  • 3
    Electronic Resource
    Electronic Resource
    Selective binding of mouse and human spermatozoa to beads coated with extracellular matrix components (1990)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 27 (1990), S. 337-343 
    Details
    ISSN: 1040-452X
    Keywords: Laminin ; Collagen ; Fibronectin ; Heparin ; Chondroitinsulfate ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The ability of mouse epididymal and human ejaculated spermatozoa to bind to beads coated with various extracellular matrix components was examined. Mouse spermatozoa preferentially bound to beads coated with heparin (average values ranging between 6.2 and 8.8 sperm per bead were obtained in different experiments) and with chondroitinsulfate (6.2-7.0), and also, although with significant differences across replicate experiments, to beads coated with laminin (7.9-15.6 sperm per bead) and with collagen type I (6.1-18.5). Human spermatozoa bound to collagen-coated beads (15.4-22.6 sperm per bead) and, to a much lower extent, to chondroitinsulfate-coated beads (3.2-4.7); they were also able to bind heparin-coated beads, although with ample differences between individual sperm donors (ranging between 0.8 and 18.7 sperm per bead). Very few human and mouse sperm bound fibronectin-coated beads; beads coated with albumin, hyaluronic acid, and chondronectin were always totally free of adhering sperm. The possible physiological role of the interactions between spermatozoa and extracellular matrix components are discussed.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1080270408
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  • 4
    Electronic Resource
    Electronic Resource
    Combined action of stem cell factor, leukemia inhibitory factor, and cAMP on in vitro proliferation of mouse primordial germ cells (1993)
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 35 (1993), S. 134-139 
    Details
    ISSN: 1040-452X
    Keywords: SCF ; LIF ; Germ cell proliferation ; Forskolin ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: In the present paper we investigated the effects of stem cell factor/mastocyte growth factor (SCF/MGF), leukemia inhibitory factor/differentiating inhibitory activity (LIF/DIA) (two growth factors known to affect primordial germ cell growth in vitro) and forskolin (FRSK) (an activator of adenylate cyclase in many cell types) alone or in combination on the survival and proliferation of primordial germ cells (PGCs) obtained from 8.5, 10.5, and 11.5 days post coitum (dpc) mouse embryos and cultured without pre-formed cell feeder layers.The results showed that both at 1 and 3 days of culture the addition of 100 ng/ml SCF, 20 μM FRSK, or in some instances 20 ng/ml LIF alone caused a significant increase of PGC number as compared with controls. The highest effects were obtained when SCF and/or LIF were used together with FRSK. Moreover, we found that FRSK elevated cAMP levels in purified 11.5 dpc PGCs and that this compound, but not SCF and LIF, stimulated PGC proliferation, as assessed by 5-bromo-2′-deoxyuridin (BrdU) incorporation.These results suggest a mechanism of combined action of cAMP with SCF and/or LIF in the control of proliferation of mouse PGCs in vitro. © 1993 Wiley-Liss, Inc.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1080350206
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  • 5
    Electronic Resource
    Electronic Resource
    “Spontaneous” hardening of the zona pellucida of mouse oocytes during in vitro culture (1982)
    New York, NY : Wiley-Blackwell
    Gamete Research 6 (1982), S. 107-113 
    Details
    ISSN: 0148-7280
    Keywords: zona pellucida ; hardening ; mouse dictyate oocytes ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Culture in vitro causes a slow, progressive hardening of the zona pellucida (ZP) of fully grown dictyate oocytes isolated from the mouse ovary. Hardening cannot be prevented by inhibitors of peroxidase or by a tyrosine analogue. Culture in anaerobic conditions is very effective in preventing ZP hardening. If the oocyte is cultured surrounded by its own follicle cells or in contact with cumuli oophori obtained from superovulated females, hardening is much reduced. The results suggest that the “spontaneous” hardening in cultured ovarian oocytes is not due to a cortical reaction, and that a diffusible factor is produced by follicle cells that protect the ZP from hardening.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120060203
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  • 6
    Electronic Resource
    Electronic Resource
    Binding of fluorescent lectins to the surface of germ cells from fetal and early postnatal mouse gonads (1984)
    New York, NY : Wiley-Blackwell
    Gamete Research 10 (1984), S. 423-432 
    Details
    ISSN: 0148-7280
    Keywords: lectins ; germ cells ; gametogenesis ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Fluorescent lectins were used to study the chemical nature of carbohydrate moieties present on the surface of female and male germ cells isolated from mouse gonads during fetal and early posnatal development. Concanavalin A (ConA), lens culinaris agglutinin (LCA), ricinus communis agglutinin (RCAI) and wheat germ agglutinin (WGA) bound intensely to the germ cell plasma membrane at all stages studied. Other lectins such as ulex europaeus agglutinin (UEAI) and agglutinin (SBA) did not bind or bound moderately (SBA to female germ cells only).Distinct developmental-related changes were observed when female germ cells were labeled with fluorescein-conjugated peanut agglutinin (PNA) or dolichos biflorus agglutinin (DBA). DBA and PNA binding was absent or weak in fetal female and male germ cells, but became intensely positive in oocytes in the immediate postnatal period. The percentage of oocytes stained with DBA increased during the first three days after birth, and from day 3-4 onwards all oocytes were strongly labeled.I suggest that these changes in lectin binding reflect changes in biochemical structure of the oocyte surface related to differentiative events occurring in the mouse ovary immediately after birth.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120100408
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  • 7
    Electronic Resource
    Electronic Resource
    Influence of cumulus cell processes on oolemma permeability and lethality of isolated mouse oocytes cultured in Ca2+-free medium (1989)
    New York, NY : Wiley-Blackwell
    Gamete Research 23 (1989), S. 245-253 
    Details
    ISSN: 0148-7280
    Keywords: zona pellucida ; cumulus cells ; calcium ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Cumulus cell processes remaining in the zona pellucida of mouse occytes mechanically isolated from the ovary have been indirectly visualized by labeling their actin microfilament core with rhodaminyl-phalloidin. If the isolation of the oocytes is performed in Ca2+-free medium, the preisence of such processes allows the entry into the cell of low molecular weight molecules (such as 5-6 carboxyfluorescein) and contributes to the death of the cell in such experimental conditions.Following dissolution of the zona pellucida (by enzymatic or acidic treatment) the oocyte is no longer permeable to small molecules and becomes resistant to Ca2+-free medium, probably as a consequence of the collapse of cumulus cell processes. The role of cumulus cell processes and gap junctions in the permeability of mechanically isolated ovarian oocytes is discussed.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120230302
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