Nuclei from HeLa and other mammalian cells have been injected into Xenopus oocytes. The synthesis, uptake, and release of RNA and proteins by injected nuclei have been investigated by autoradiography. Injected nuclei which undergo enlargement synthesize RNA continuously for up to 28 days. When oocytes are incubated in [3H]uridine or [3H]guanosine, injected nuclei are labelled nearly as strongly...

Cep55 is a relatively novel member of the centrosomal protein family. Here, we show that Cep55 is expressed in mouse oocytes from the germinal vesicle (GV) to metaphase II (MII) stages. Immuostaining and confocal microscopy as well as time lapse live imaging after injection of mRNA encoding fusion protein of Cep55 and GFP identified that Cep55 was localized to the meiotic spindle, especially to...

BACKGROUND Somatic cell nuclear transfer (SCNT) involves the transfer of somatic cell nuclei into enucleated oocytes. Because human in vivo matured oocytes are scarcely available, we investigated whether in vitro matured (IVM) germinal vesicle (GV) oocytes could also support preimplantation development of human cloned embryos. METHODS Three groups were used for SCNT: in vitro matured GV oocyt...

Background: Effect of different doses of cysteamine on rate of in vitro maturation (IVM), in vitro fertilization (IVF) and glutathione (GSH) level was studied. Metaphase II (MII) spindle area was analyzed for quantification of shape and size of oocytes. Methods: Female mice were primed with 5 IU of pregnant mare’s stimulating gonadotrophin. Germinal vesicle (GV) oocytes were retrieved 48 hrs la...

The resumption of meiosis in Xenopus arrested oocytes is triggered by progesterone, which leads to polyadenylation and translation of Mos mRNA, then activation of MAPK pathway. While Mos protein kinase has been reported to be essential for re-entry into meiosis in Xenopus, arrested oocytes can undergo germinal vesicle breakdown (GVBD) independently of MAPK activation, leading us to question wha...

background: the utilization of immature oocytes derived from stimulated cycles could be of great importance, specially for urgent fertility preservation cases. the aim of the current study was to determine whether in-vitro maturation is more successful before or after the vitrification of these oocytes. materials and methods: the study was performed in a private ivf center. 318 germinal vesicle...