We recently identified Xenopus Rho-associated protein kinase alpha (xROKalpha) as a Xenopus insulin receptor substrate-1 binding protein and demonstrated that the non-catalytic carboxyl terminus of xROKalpha binds Xenopus insulin receptor substrate-1 and blocks insulin-induced MAP kinase activation and germinal vesicle breakdown in Xenopus oocytes. In the current study we further examined the r...

High resolution two-dimensional electrophoresis has been used to examine the pattern of protein synthesis during meiotic maturation of mouse oocytes in vitro. Fluorograms of [35S]methionine-labeled oocyte proteins have revealed that meiotic progression from dictyate to metaphase II (meiotic maturation) is accompanied by marked changes in the pattern of proteins synthesized by oocytes. Virtually...

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. ...

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...

objective: mitochondria is a critical organelle within the cell and has important role in the oocyte development, thus the aim of this study was the comparison of mitochondrial distribution within the mouse oocyte at germinal vesicle (gv), germinal vesicle breakdown (gvbd) and metaphase ii (mii) stages using laser confocal microscopy (lscm). materials and methods: after superovulation of adult...

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 ...

Nuclear transfer procedures have been recently applied for clinical and research targets as a novel assisted reproductive technique and were used for increasing the oocyte activity during its growth and maturation. In this review, we summarized the nuclear transfer technique for germinal vesicle stage oocytes to reconstruct the maturation of them. Our study covered publications between 1966 and...

objective: retinoids are recognized as important regulators of cell differention and tissue function. previous studies, performed both in vivo and in vitro, indicate that retinoids influence several reproductive events. in this study, we investigated the effect of all-trans retinoic acid (t-ra) on maturation and fertilization rate of immature oocytes (germinal vesicle). materials and methods: g...

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...

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 ...