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  • 1
    Electronic Resource
    Electronic Resource
    [s.l.] : Nature Publishing Group
    Nature 221 (1969), S. 981-982 
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] SIR,-We consider the earlier stages of fertilization include attachment of spermatozoa to the zona pellucida, their movement through it and the presence of spermatozoa in the perivitelline space. Our data1 gave convincing evidence in many eggs of the accomplishment of these earlier stages, and this ...
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    [s.l.] : Nature Publishing Group
    Nature 221 (1969), S. 632-635 
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Human oocytes have been matured and fertilized by spermatozoa in vitro. There may be certain clinical and scientific uses for human eggs fertilized by this ...
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 31 (1992), S. 200-207 
    ISSN: 1040-452X
    Keywords: Protein-free medium ; BSA ; In vitro sperm penetration ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The ability of domestic cat or leopard cat spermatozoa to penetrate zonae pellucidae (ZP) of salt-stored, domestic cat oocytes was examined as an assay for sperm capacitation. Ovarian oocytes were recovered after ovariectomy and matured in vitro for 18-36 h. Following removal of cumulus cells, the oocytes were used fresh, or stored (4°C, 0.5-24 weeks) in a HEPES-buffered hypertonic salt solution. Electroejaculated, washed sperm (2-4 × 106 sperm/ml) were preincubated for 1.0 h (38°C, 5% CO2 in air) and then co-incubated (2 × 105 sperm/ml) with fresh or stored oocytes for 6.0 h. Gametes were incubated in a protein-free, modified Tyrode's solution (TLP-PVA) or in the same medium containing 4.0 mg/ml bovine serum albumin (BSA; TALP-PVA). Treatments were compared for percentage ZP penetration (defined as sperm heads reaching more than halfway through the ZP) as an index of sperm capacitation. In both the domestic cat and leopard cat, there was no difference (P 〉 0.05) in sperm penetration of fresh ZP (domestic cat, 42.5 ± 5.4%; leopard cat, 38.6 ± 2.8%) or stored ZP (domestic cat, 32.4 ± 4.2%; leopard cat, 27.6 ± 2.3%). Sperm incubated in protein-free medium (TLP-PVA) were less capable (P〈0.05) of ZP penetration (domestic cat, 14.6 ± 5.9%; leopard cat, 7.9 ± 3.0%) than sperm incubated in medium TALP-PVA containing BSA (domestic cat, 60.3 ± 5.9%; leopard cat, 58.4 ± 3.0%). These data indicate that (1) albumin facilitates capacitation and ZP penetrating ability of cat spermatozoa; (2) domestic cat ZP appear to lack a block to heterospecific penetration by “foreign” (leopard cat) sperm; and (3) penetration of stored domestic cat ZP can be used as an index of sperm capacitation in the domestic cat and the leopard cat.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Gamete Research 18 (1987), S. 333-338 
    ISSN: 0148-7280
    Keywords: abnormal meiosis ; polyspermy ; hamster ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The occurrence of second polar body (PB2) retention in in-vitro fertilized hamster eggs is reported. Of 2,872 eggs examined, 6.9% (199 eggs) failed to extrude PB2. Eggs that failed to extrude PB2 were more likely to be polyspermic than eggs with PB2 (63% and 14.6%, respectively), and the number of fusing sperm per egg was higher in the abnormal eggs. These data indicate that eggs which fail to extrude PB2 have an impaired block to polyspermy. The level of PB2 retention varied between females and ranged from all eggs extruding PB2 to 20% of the eggs failing to extrude PB2 (41% and 4% of the females, respectively). There was no correlation within a female between the percentage of eggs that failed to extrude PB2 and the level of polyspermy in the sister eggs with PB2. Therefore, regardless of the condition of their sister eggs, eggs that fail to extrude PB2 have an impaired block to polyspermy and eggs that extrude PB2 have a normal block.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Gamete Research 19 (1988), S. 235-240 
    ISSN: 0148-7280
    Keywords: oviductal factors ; in vitro development ; organ culture ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Hamster early two-cell embryos developed to the expanded blastocyst stage within the isolated mouse ampulla maintained in organ culture system. Mouse ampullae isolated at different times after treating the mice with human chorionic gonadotropin (hCG) (0-72 h) or pregnant mare's serum gonadotropin (PMSG) (30-32 h) were flushed with culture medium, and hamster early two-cell embryos were introduced into these ampullae. Mouse ampullae isolated at 14-32 h after hCG injection were more favorable for the development of the embryos than those isolated at 70-72 h. When mouse ampullae were isolated 30-32 h after hCG or PMSG treatment, 39% of the cultured eggs developed, some of them to the expanded blastocyst stage after additional culture for 65-70 h. These results indicate that unknown oviductal factors stimulate the development of hamster early two-cell embryos, and these factors are under the control of hCG or PMSG. In addition, these factors are common to the mouse and hamster.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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