Ca(2+)-dependent mechanisms are critical for successful completion of fertilization. Here, we demonstrate that CRISP1, a sperm protein involved in mammalian fertilization, is also present in the female gamete and capable of modulating key sperm Ca(2+) channels. Specifically, we show that CRISP1 is expressed by the cumulus cells that surround the egg and that fertilization of cumulus-oocyte comp...

Immature oocytes benefit from nutrient modification of the follicular environment by the surrounding cumulus mass. However, the oxygen concentration that the oocyte may be exposed to could be lower than the antral follicular concentration due to the metabolism of surrounding cumulus cells. Using metabolic data previously determined, we have developed a mathematical model of O(2) diffusion acros...

Background: Cryopreservation of ovaries is an important technique in assisted reproduction technology. Physical forces like hydrostatic pressure have a pivotal role in reproduction systems. Due to changes in intrafollicular pressure during ovulatory process, this study designed to examine the effects of hydrostatic pressure on oocyte maturation and cell death in cumulus cells from cryopreserved...

Impaired oocyte quality has been demonstrated in diabetic mice; however, the potential pathways by which maternal diabetes exerts its effects on the oocyte are poorly understood. Cumulus cells are in direct contact with the oocyte via gap junctions and provide essential nutrients to support oocyte development. In this study, we investigated the effects of maternal diabetes on the mitochondrial ...

background: the mitogen-activated protein kinase (mapk) pathway is one of the major signaling pathways that transmit intracellular signals initiated by extracellular stimuli to the nucleus. the stress-activated protein kinase (sapk)/c-jun nh2-terminal kinase is a subfamily of map kinases implicated in cytokine and stress responses. objective: in this study, we have examined total and phosphoryl...

Background: The effects of cumulus cells and the effectiveness of a PDE3 specific inhibitor (Cilostamide) in comparison with an adenylate cyclase activator (Forskolin) on the maturation rate and developmental competence of mouse germinal vesicle (GV) oocytes were evaluated Materials and Methods: Germinal vesicles (GV) oocytes of PMSG-primed mice were divided into cumulus denuded oocytes (CDOs) ...

Because latent form of matrix metallopeptidase-9 (proMMP9) levels are positively related to blastocyst development, it was hypothesized that addition during maturation may improve development of heat-stressed oocytes. To test hypothesis, 0, 30 or 300 ng/ml human proMMP9 (hMMP9) was added at 18 h of in vitro maturation (hIVM) to cumulus-oocyte complexes matured at 38.5 or 41.0ºC (first 12 h only...

Background: The efficiency of in vitro maturation (IVM) has remained low despite extensive effort to understand the culture conditions. This study investigated the effect of cumulus cells and meiotic inhibitors on oocyte developmental competence in the presence of Alpha Lipoic acid (ALA) Materials and Methods: Mouse germinal vesicle oocytes were considered in cumulus-denuded oocytes (CDOs) and ...