Some culture systems have been shown to support oocyte growth in mice, although there has been little success in applying these systems to other species. In the present study, we compared three culture conditions for growing bovine oocytes and examined the effect of hypoxanthine on oocyte growth. In the first experiment, early antral follicles, 0.4-0.7 mm in diameter were collected, and oocyte-...

Background: The efficiency of in vitro maturation (IVM) has remained low despite extensive effort to understand the culture conditions. This study investigated the effect of cumulus cells and meiotic inhibitors on oocyte developmental competence in the presence of Alpha Lipoic acid (ALA) Materials and Methods: Mouse germinal vesicle oocytes were considered in cumulus-denuded oocytes (CDOs) and ...

conclusions the present study showed that vitrification using cryotop and freezing medium can damage oocytes by reducing the maturation and fertilization rates in both developmental stages. results vitrification caused a significant reduction in the maturation rate of oocytes. of those that matured, the fertilization rate of vitrified ivm-mii (44.1%) and ov-mii oocytes (50%) was not significant...

background: the aim of this study was to assess effects of cysteamine as an anti-oxidant on rate of in vitro maturation of oocyte and determination of its effects on spindle size and shape. methods: pre-mature mice were primed with pregnant mare stimulating gonadotrophin (pmsg) and germinal vesicle (gv) stage oocytes were obtained 48 h after. the oocytes were cultured in tissue culture medium (...

Positive transcription elongation factor b (P-TEFb) is a RNA polymerase II carboxyl-terminal domain (Pol II CTD) kinase that phosphorylates Ser2 of the CTD and promotes the elongation phase of transcription. Despite the fact that P-TEFb has role in many cellular processes, the role of this kinase complex remains to be understood in mammalian early developmental events. In this study, using immu...

A study was conducted opportunistically to evaluate the potential of rescuing immature oocytes from the ovaries of the Sumatran rhinoceros postmortem. Recovered oocytes (n = 30) were placed in maturation culture for 36 hr and inseminated with frozen-thawed homologous spermatozoa. After culture, evaluation of nuclear maturation status revealed that a large number of oocytes were degenerated (n =...

Cortical granules are secretory vesicles formed in the eggs of most animals and are essential for the prevention of polyspermy in these organisms. We have studied the biogenesis of cortical granules in sea urchin oocytes by identifying cDNA clones that encode proteins targeted selectively to the cortical granules. These cDNA clones were identified by an immunoscreen of a cDNA library using anti...

Cortical granules are secretory vesicles poised at the cortex of an egg that, upon stimulation by sperm contact at fertilization, secrete their contents. These contents modify the extracellular environment and block additional sperm from reaching the egg. The role of cortical granules in blocking polyspermy is conserved throughout much of phylogeny. In the sea urchin, cortical granules accumula...

Total inhibition of germinal vesicle breakdown (GVBD) was observed in growing pig oocytes (internal diameter 80, 90 and 100 microns) when they were cultured in a medium conditioned by cumulus oocyte complexes (COCs) of fully grown oocytes. In denuded growing oocytes, only partial inhibition was observed. The inhibitory effect was fully reversible. The addition of heparin (300 IU/ml) could overc...

OBJECTIVE This study was aimed to determine the effects of n-hexane on the maturation of mouse oocytes. METHODS Cell culture was used to observe the maturation of mouse oocytes and CLSM was employed to determine their apoptosis. RESULTS Germinal vesicle breakdown (GVBD) and extrusion of the first polar body in mouse oocytes were significantly inhibited by n-hexane. After fertilization, the ...