rate of in vitro maturation of oocytes is one of the challenges of assisted reproductive techniques. in this study we investigated the effects of supplementation of cysteamine on the rate of in vitro maturation of oocytes in two different media. germinal vesicle oocytes were collected from mouse ovary and cultured in two media (tcm199 and meme) with 0, 50, 100, 200, 500 µm/ml cysteamine. number...

It is demonstrated that the microinjection of cytoplasm from competent, fully grown oocytes can induce germinal vesicle breakdown in meiotically incompetent growing oocytes. Injection of cytoplasm from oocytes at methaphase I had a similar effect. The maturation in injected growing oocytes was arrested at the premetaphase or metaphase I stage. Induction of germinal vesicle breakdown by cytoplas...

The starfish oocyte is relatively clear optically, and its nucleus, termed the germinal vesicle, is large. These characteristics allowed studies by confocal microscopy of germinal vesicle breakdown during maturation in living oocytes. Three fluorescent probes for cytoplasmic components were used: fluorescein 70 kDa dextran, which does not cross the nuclear pore of immature oocytes and probably ...

In this study, we investigated the spatio-temporal distribution of conventional protein kinases C (cPKC) isoforms PKC-alpha, PKC-betaI, PKC-betaII and PKC-gamma in mouse oocytes. The cPKCs were present in the cytoplasm at the start of the process and migrated to the nucleus (or germinal vesicle) before germinal vesicle breakdown, except for PKC-gamma which remained cytoplasmic. In both compartm...

Background: Polycystic ovary syndrome (PCOS) is characterized by chronic anovulation and hyperandro genism and affects approximately 5-10% of women of reproductive age. In vitro maturation (IVM) of mammalian oocytes has become an efficient method to produce mature oocytes in order to use in assisted reproductive techniques such as in vitro fertilization (IVF), intra cytoplasmic sperm injection ...

In vitro studies of meiotic maturation of mouse oocytes have been carried out in the presence of several drugs. The individual steps of nuclear progression, including dissolution of the nuclear (germinal vesicle) membrane, condensation of dictyate chromatin into compact bivalents, formation of the first metaphase spindle, and extrusion of the first polar body, are each susceptible to one or mor...

In mammalian females, germ cells remain arrested as primordial follicles. Resumption of meiosis is heralded by germinal vesicle breakdown, condensation of chromosomes, and their eventual alignment on metaphase plates. At the first meiotic division, anaphase-promoting complex/cyclosome associated with Cdc20 (APC/CCdc20) activates separase and thereby destroys cohesion along chromosome arms. Beca...

a:4:{s:10:"Background";s:206:"The aim of the present study was to investigate the role of progesterone on the developmental competence of cumulus-oocyte complexes (COCs) and cumulus-denuded oocytes (CDOs) at germinal vesicle (GV) stage.";s:19:"MaterialsAndMethods";s:485:"GV oocytes of pregnant mare's serum gonadotropin (PMSG)-primed prepubertal mice were divided into two groups: CDOs and COCs. ...