BACKGROUND In spite of extensive efforts to improve in vitro oocyte maturation, the obtained results are not very efficient. This study was conducted to assess impacts of cAMP elevating agents and alpha lipoic acid (ALA) on in vitro oocyte maturation and fertilization. METHODS Mouse germinal vesicle (GV) oocytes were categorized into cumulus denuded oocytes (DOs; n=896) and cumulus oocyte com...

Vertebrate eggs arrest at metaphase of the second meiotic division before fertilization under the effect of a cytostatic factor (CSF). This arrest is established during oocyte maturation by the MAPK kinase module, comprised of Mos, MEK, MAPKs and p90Rsk. Maintenance of CSF arrest at metaphase requires inhibitors of the anaphase-promoting complex (APC) like Emi1, which sequesters the APC activat...

Vertebrate eggs arrest at metaphase of the second meiotic division before fertilization under the effect of a cytostatic factor (CSF). This arrest is established during oocyte maturation by the MAPK kinase module, comprised of Mos, MEK, MAPKs and p90. Maintenance of CSF arrest at metaphase requires inhibitors of the anaphase-promoting complex (APC) like Emi1, which sequesters the APC activator ...

introduction: the incidence of sperm and oocyte premature chromosome condensation (pcc) in the failed fertilized oocytes that were taken after routine in viro fertilization (ivf) and intracytoplasmic sperm injection (icsi) programs were investigated. materials and methods: in this study, 364 air-dried preparations of failed fertilized oocytes after either ivf or ocsi procedures were analyzed. t...

Mammalian oocytes are arrested in meiotic prophase by an inhibitory signal from the surrounding somatic cells in the ovarian follicle. In response to luteinizing hormone (LH), which binds to receptors on the somatic cells, the oocyte proceeds to second metaphase, where it can be fertilized. Here we investigate how the somatic cells regulate the prophase-to-metaphase transition in the oocyte, an...

Maintaining and restore the full developmental competence of either mature or immature oocytes after cryopreservation processes to preserve women fertility is a goal in assisted reproductive technologies (ART). This goal arises from the need of some patients to preserve their oocytes before arriving to a reproductively mature age, such as patients who need to undergo chemotherapy. Although in v...

The developmental competence of in vitro-matured (IVM) rhesus macaque cumulus oocyte complexes (COCs) is deficient compared with in vivo-matured (IVM) oocytes. To improve oocyte quality and subsequent embryo development following IVM, culture conditions must be optimized. A series of experiments was undertaken to determine the role of epidermal growth factor (EGF) during IVM of rhesus macaque C...

The aim of this study was to evaluate the effects of ovarian tissue vitrification and two-step in vitro culture on the metaphase II (MII) oocyte reactive oxygen species (ROS) level, mitochondrial transcription factor A (TFAM) expression and succinate dehydrogenase (SDH) activity. After collection of neonatal mouse ovaries, 45 ovaries were vitrified and the others (n = 45) were...

Mammalian oocytes are arrested in meiotic prophase for prolonged periods, and then resume meiosis in response to luteinizing hormone from the pituitary, which binds to the somatic cells surrounding the oocyte. This chapter reviews current knowledge and questions about the molecular mechanisms that mediate communication between the somatic cells and oocyte to control the prophase-to-metaphase tr...