Activation of p34 protein kinase activity in meiotic and mitotic cell cycles in mouse oocytes and embryos

Activation of p34cdc2 protein kinase activity in meiotic and mitotic cell cycles in mouse oocytes and embryos.

p34cdc2 protein kinase is a universal regulator of M-phase in eukaryotic cell cycle. To investigate the regulation of meiotic and mitotic cell cycle in mammals, we examined the changes in phosphorylation states of p34cdc2 and its histone H1 kinase activity in mouse oocytes and embryos. We showed that p34cdc2 has three different migrating bands (referred to as upper, middle and lower bands) on S...

Tyrosine phosphorylation of p34and p42 during meiotic maturation of Xenopus oocyte Antagonistic action of okadaic acid and 6-DMAP

The tyrosine phosphorylation/dephosphorylation of p34 was estimated by immunoblotting with antiphosphotyrosine antibody during meiotic maturation of Xenopus oocytes. At the time of germinal vesicle breakdown (GVBD), p34 is tyrosine dephosphorylated whereas a p42 protein, which might correspond to a MAP2 kinase, becomes tyrosine phosphorylated. No modification in the level of tyrosine phosphoryl...

Mouse Oocytes and Embryos Cryotop-vitrification Using Low Concentrated Solutions: Effects on Meiotic Spindle, Genetic Material Array and Developmental Ability

P-76: Cytogenetic Investigation of Parthenogenetic Mouse Embryos Generated from In Vitro Activated Oocytes by Hydrostatic Pressure in The Presence of Calcium Ionophore and Ethanol

Background: The advances in cytogenetic techniques during the last few years have permitted not only the study of large populations of wild and domestic animals, but also the detection of chromosome anomalies in embryos. Chromosomal abnormalities are the most common cause of embryonic and fetal mortality in mammals. Most reports of chromosome anomalies in parthenogenetic embryos describe numeri...

P-229: Chromosomal Analysis of Parthenogenetic Mouse Embryos Generated from In Vitro Activated Oocytes by Hydrostatic Pressure and Ethanol and Cytochalasin B

Background: Studies of preimplantation stage embryos by classic cytogenetic techniques have limitations, starting with the need for good metaphase stage when only one third of all analyzed embryos may show good quality metaphases. The incidence of chromosome anomalies in embryos produced by in vitro procedures is generally higher than that of embryos formed in vivo. Pressure specifically affect...