Sperm chemotaxis in mammals have been identified towards several female sources as follicular fluid (FF), oviduct fluid, and conditioned medium from the cumulus oophorus (CU) and the oocyte (O). Though several substances were confirmed as sperm chemoattractant, Progesterone (P) seems to be the best chemoattractant candidate, because: 1) spermatozoa express a cell surface P receptor, 2) capacita...

The molecular and structural changes in the follicle triggered by the gonadotropin luteinizing hormone (LH) at ovulation require complex interactions between somatic cells and the oocytes. It is well established that the signals originating from the oocytes play an essential role in orchestrating the growth and development of the follicle. Conversely, the exact contribution of local signals in ...

OBJECTIVE In this study, we aimed to evaluate the influence of autologous cumulus oocyte complex (COC) coculture on embryonic development and quality, and investigate the implantation and pregnancy rates after cumulus-aided embryo transfer in the ICSI-ET cycles. MATERIAL AND METHODS Ninety five consecutive infertile women undergoing their first cycle of IVF teratment were included in the stud...

Mitochondrial quality control is important for maintaining cellular and oocyte viability. In addition, aging affects mitochondrial quality in many cell types. In the present study, we examined how aging affects oocyte mitochondrial biogenesis and degeneration in response to induced mitochondrial dysfunction. Cumulus oocyte complexes were harvested from the ovaries of young (21‒45 months) and ag...

Mitochondria provide the primary source of ATP in the oocyte and early embryo and mitochondrial dysfunction and deficit of mitochondria-derived ATP has been linked to suboptimal developmental competence. We have undertaken a study of ATP in the maturing mouse oocyte using a novel recombinant FRET based probe, AT1.03. We show that AT1.03 can be successfully used to monitor cytosolic ATP levels i...

Prior to ICSI the cumulus-oophorous-complex of the oocyte is commonly remove with impure animal-derived hyaluronidase of low strength. The lower strength of the enzyme, the high concentration of impurities and the necessity of extensive time-dependent mechanical denudation damages of the oocytes, increases the risk of lysing the oocytes and the transfer of animal-derived pathogens. All this can...

The Arp2/3 complex regulates actin nucleation, which is critical for a wide range of cellular processes, such as cell polarity, cell locomotion, and endocytosis. In the present study, we investigated the possible roles of the Arp2/3 complex in porcine oocytes during meiotic maturation. Immunofluorescent staining showed the Arp2/3 complex to localize mainly to the cortex of porcine oocytes, colo...

Ovulation is the complex, inflammatory-like process by which the cumulus oocyte complex (COC) is released from a mature, preovulatory follicle through a rupture site at the ovarian surface and requires expression of genes that generate and stabilize the expanded extracellular COC matrix. Gene profiling analyses of COCs at selected time intervals during ovulation revealed that many genes associa...

The mechanisms underlying the hormonal stimulation of meiotic maturation are not understood. The most prevalent hypothesis is that hormone-induced maturation is stimulated by an increase in the intracellular messengers, cAMP or Ca2+. This study investigated whether Ca2+ transients in somatic cells can lead to Ca2+ transients in the oocyte, and whether hormones that stimulate meiotic maturation ...

OBJECTIVE To relate the gene expression in cumulus cells surrounding an oocyte to the potential of the oocyte, as evaluated by the embryo morphology (days 3 and 5) and pregnancy obtained in single-embryo transfer cycles. DESIGN Retrospective analysis of individual human cumulus complexes using quantitative real-time polymerase chain reaction for 11 genes. SETTING University hospital IVF cen...