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  • 1
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 39 (1994), S. 25-29 
    ISSN: 1040-452X
    Keywords: Hemizona assay (HZA) ; Rhesus monkey ; Oocyte ; Sperm ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The hemizona assay (HZA) in Rhesus monkeys was employed to study the correlation of zona-binding ability with sperm motility or with naturally developing oocytes at various maturational stages. Oocytes from unstimulated ovaries were retrieved within 2 hr from monkeys sacrificed for vaccine production (in reproductive season, but with their menstrual cycles not determined). Oocytes were divided into four groups based on their morphological maturation: 1) Oocytes surrounded by more than one cumulus layer (MC); 2) Oocytes retaining intact germinal vesicle nuclei (GV); 3) Oocytes with germinal vesicle breakdown showing distinct perivitelline space (PVS); and 4) Oocytes extruding the first polar body (PBI). The mean numbers of sperm bound to hemizona for PB1, PVS, GV, and MC groups were 132.9 ± 12.0, 71.5 ± 10.1, 36.1 ± 4.0, and 20.1 ± 2.9 (Mean ± SE), respectively. The four groups showed significant differences from each other in sperm/egg binding ability (P 〈 0.01). The number of bound sperm significantly increased with oocyte maturation. The present study also showed that zona-binding ability was also affected by sperm motility. For sperm with 67.7% motility and sperm with 31.2% motility, the average numbers of bound sperm were 43.5 ± 2.2 and 25.3 ± 2.9 (Mean ± SE), respectively. There was significantly higher binding ability for sperm with higher motility (P 〈 0.01). The results suggest that: 1) The rhesus monkey model can serve as a very sensitive model for studying sperm/egg interaction by HZA; 2) Sperm motility positively correlated with sperm/egg binding; and 3) Sperm/egg binding ability increases with oocyte maturation. The binding ability is highest when oocytes matured to the PB1 stage, which is also the best opportunity for fertilization. This is strong evidence for the “zona maturation” hypothesis. © 1994 Wiley-Liss, Inc.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Molecular Reproduction and Development 27 (1990), S. 110-117 
    ISSN: 1040-452X
    Keywords: Rabbit embryos ; Hypertonic sucrose ; Micromanipulation ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Rabbit zygotes and embryos were exposed to hypertonic sucrose in phosphate-buffered saline (SPBS). In experiment one, 144 zygotes shrank to 32-36% of their initial volume in 1.0 M SPBS within 30 min. Neither hypertonic treatment with 0.5 M or 1.0 M SPBS nor micropuncture of the zona pellucida after shrinkage affected embryo development into blastocysts in vitro (88%, 83%, and 82%, respectively), compared to that of the controls (93%, P 〉 .05). In experiment two, 252 two- to four-cell- and 177 morula-stage embryos were exposed to isotonic PBS control or 0.5 M, 1.0 M, or 1.5 M SPBS for 30, 60, 90, 120, and 150 min before transfer to PBS (290 mOsm). Embryo development was significantly reduced (P 〈 .05) when embryos were exposed in 0.5 M and 1.0 M SPBS for more than 60 min or in 1.5 M SPBS for more than 30 min. In experiment 3, morulae exposed for 60 min to 0.5 M or 1.0 M SPBS shrank to 37-39% or 32-35% of their initial volume and then expanded to 87-94% or 81-90% of their initial volume, respectively, after being returned to isotonic PBS for 60 min, but embryos in 1.5 M SPBS had erratic osmotic behavior. In experiment four, 192 two- to four-cell embryos exposed to 0.5 M SPBS for 0, 30, and 60 min before transfer to oviducts of recipients resulted in the production of 39%, 42% and 31% young, respectively (P 〉 .05). Exposure of embryos to 0.5 M sucrose for 60 min clearly does not compromise developmental potential and can simplify and speed up micromanipulation procedures.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 134 (1988), S. 189-199 
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The growth of tissue culture TO-2 cells derived from the warm water fish Tilapia, the induction of thermotolerance, and protein synthesis profiles of these cells in response to temperature changes were examined. TO-2 cells can grow between 15 to 34°, with an optimal growth temperature of 31°. There is no apparent killing of the cells when the temperature is lowered to 4° for up to 3 days. Survival of TO-2 cells at 43° was studied after various preheat treatments: (1) acute heating at 40° for 15 min followed by 31° incubation, (2) chronic exposure at 37° for several hr, or (3) long-term thermal adaptation at 34°. The cells acquire thermotolerance from pre-exposure to 37° for as short as 6 hr. Preheating at 40° followed by incubation at 31° also induces thermotolerance against a subsequent 43° heat challenge. In addition, 34° thermal adapted cells are resistant to 43° heating. One- and two-dimensional gel electrophoresis of proteins after heat treatments show that three major heat shock proteins with molecular weights around 87, 70, and 27 kD are preferentially synthesized. The synthesis of two additional proteins with an isoelectric point of 6.9 and molecular weights of 60 and 44 kD are significantly enhanced in 34° thermal-adapted and 37° chronic heated cells, but not in cells subjected to an acute heat shock at either 40° or 43°. On the other hand, the 27 kD heat shock proteins are mainly present in the 43°, 40°, and 37° heat-shocked cells, but not in the 34° thermal-adapted cells.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
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