background: routine oocytes cryopreservation remained an elusive technique in the wide ranges of available assisted reproductive technologies. the microtubules of oocytes are vulnerable to cryoprotectants and thermal change during cryopreservation. objective: the effects of a vitrification protocol were investigated on the spindle and chromosome configurations of mice oocytes cryopreserved at t...

Spawning was induced in both male and female Pismo clams by injecting 0.4 ml of 5 mM serotonin into the gonad. Spawned oocytes had already matured to metaphase I of meiosis or were undergoing germinal vesicle breakdown at the time of release. Prophase-arrested oocytes scraped from the ovaries of uninjected clams were induced to undergo germinal vesicle breakdown in vitro by incubating them with...

The regulation of the cell cycle during the transition from prophase to metaphase I was studied by analysing protein changes and introducing protein blocks during the transition phase. The results show that the progression to metaphase in ovine oocytes is totally dependent on new protein synthesis. By delaying the addition of the inhibitor, cycloheximide, for progressively longer periods after ...

Polychlorinated biphenyls (PCBs) are endocrine-disrupting chemicals that mimic estrogen in fish. Among the various PCBs, 3,3’,4,4’,5-pentachlorobiphenyl (PCB126), considered an antagonist, has been reported to elicit estrogenic activity We investigated potency of PCB126 vitro oocyte maturation dusky tripletooth goby, Tridentiger obscurus . In this study, we quantified steroid metabolites follow...

in order to determine the most effective hormones on the in vitro oocyte maturation (germinal vesicle breakdown - gvbd) in a hybrid sturgeon bester, ovarian follicles were incubated at the migratory nucleus stage in the presence of several steroids, gonadotropin preparations and forskolin. occurrence of gvbd and 17,20β-dihydroxy-4-pregnen-3 -one (dhp) production were followed during an expe...

Although securin/separase/cohesion pathway was reported to regulate chromosome segregation during meiotic metaphase-to-anaphase transition, little biochemical evidence was provided. We recently found that oocytes could not progress beyond meiotic metaphase when ubiquitin-proteasome pathway was inhibited, but the mechanisms remain unclear. In the present study, we investigated the quantity of se...

This study examines the timing of changes in chromosome configurations of pig oocytes derived from small antral follicles of follicular and/or inactive stage donors using modified 199 medium supplemented with gonadotropins (Follicle Stimulating Hormone (FSH), 10 IU/ml; Human Chorionic Gonadotropin (hCG), 10 IU/ml) and Glucosamine (0.539 mg/ml). Oocytes (n = 1,215) were fixed at the end of 3 hou...