In amphibians, as well as in other vertebrates, occytes start to mature under the action of hypophyseal gonadotropic hormones. (In this paper the term 'maturation' implies the transformation into ripe eggs of oocytes that have finished growing.) In the course of maturation the oocytes themselves and the follicle cells surrounding them undergo changes; the changes of these two cell types are not...

BACKGROUND In assisted reproductive techniques, 85% retrieved oocytes are mature, and the rest are immature. These immature oocytes may be matured in vitro, and used in subsequent in vitro fertilization program. The purpose of this study was to determine the maturation capacity and morphology of human immature oocytes in both fresh and vitrified-thawed, in vitro matured oocytes with regard to t...

Background In vitro maturation (IVM) of human oocytes has acquired increasing attention in infertility treatment with great promise. This technique is an alternative conventional in vitro fertilization-embryo transfer (IVF-ET), and can be reduced the side effects of gonadotropin stimulation such as ovarian hyperstimulation (OHSS). Oocyte maturation is a complex process including cytoplasmic and...

Germinal vesicle breakdown in mouse oocytes in vivo and in vitro has been examined by electron microscopy. In vitro oocytes were studied immediately after release from follicles and at various times (05-11 h) in culture. Approximately 30 min after oocyte release, chromatin condensation begins along the convoluted nuclear envelope (NE). Chromatin granules are common in all condensing chromosomes...

objective: this study evaluated in vitro maturation (ivm) of oocytes in the germinal vesicle (gv) stage in stimulated intracytoplasmic sperm injection (icsi) cycles. materials and methods: a total of 26 women, aged 18 -37 years, who were candidates for icsi at the fatemeh zahra infertility and health reproductive research center in 2007 were recruited for this study. we used the standard long p...

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...

PURPOSE OF REVIEW To evaluate current and previous findings related to a timely implementation of in-vitro maturation (IVM) of germinal vesicle, metaphase I and metaphase II oocytes with an optimal cryopreservation to determine whether IVM should be attempted prior to (fresh IVM) or IVM after cryopreservation (postthaw IVM). Mitochondrion, chromatin and spindle formation in both groups were int...

Keeping the intact germinal vesicle (GV) is essential for maintaining the capacity of mammals including human. It is maintained by very complex procedures along with folliculogenesis and is a critical step for getting competent oocyte. So far, a few mechanisms involved in folliculogenesis are known but GV arrest mechanisms are largely unrevealed. Cyclic AMP, a adenosine derived substance, have ...

Germinal vesicle breakdown (GVBD) of bovine oocytes was completely blocked by cycloheximide added to culture medium at concentrations of 1-20 micrograms/ml. Nevertheless, under such conditions a certain degree of chromatin condensation inside the germinal vesicle was observed. The inhibitory effect was not influenced by the presence or absence of cumulus cells and was fully reversible; but the ...