BACKGROUND Shortly after stimulation by the preovulatory surge of luteinizing hormone (LH), oocytes arrested at the late prophase I resume meiosis characterized by germinal vesicle breakdown (GVBD), chromosome condensation, and extrusion of the first polar body in preparation for fertilization and early embryonic development. However, oocytes express few or no LH receptors and are insensitive t...

Calcium oscillations occur during meiotic maturation of mouse oocytes. They also trigger activation at fertilization. We have monitored [Ca2+]i in oocytes at different stages of growth and maturation to examine how the calcium release mechanisms alter during oogenesis. Spontaneous calcium oscillations occur every 2-3 minutes in the majority of fully grown (but immature) mouse oocytes released f...

The maintenance of meiotic prophase arrest in mouse oocytes within fully grown follicles, prior to the surge of luteinizing hormone (LH) that triggers meiotic resumption, depends on a high level of cAMP within the oocyte. cAMP is produced within the oocyte, at least in large part, by the G(s)-linked G-protein-coupled receptor, GPR3. Gpr3 is localized in the mouse oocyte but is also present thro...

Objective Many autocrine and paracrine elements that are produced within follicular niche have been the focus of much in vitro maturation research. The present study was carried out to compare retinoic acid and basic fibroblast growth factor (bFGF) efficacy on IVM of mouse oocytes, and their further dual consumption to reach an optimal protocol. MaterialsAndMethods GV oocytes obtained from two-...

Oocyte freezing confers thermal and chemical stress upon the oolemma and various other intracellular structures due to the formation of ice crystals. The lipid profiles of oocytes and embryos are closely associated with both, the degrees of their membrane fluidity, as well as the degree of chilling and freezing injuries that may occur during cryopreservation. In spite of the importance of lipid...