Cell-to-cell communication was characterized in cumulus-oocyte complexes from rat ovarian follicles before and after ovulation. Numerous, small gap junctional contacts were present between cumulus cells and oocytes before ovulation. The gap junction are formed on the oocyte surface by cumulus cell processes that transverse the zona pellucida and contact the oolemma. The entire cumulus mass was ...

Porcine immature oocyte quality (i.e., that of live oocytes at the germinal vesicle stage) was evaluated according to features of the surrounding cumulus, aiming to establish maturational competence of different subpopulations of such cumulus-oocyte complexes. Six subpopulations were identified: A1 (with a dense cumulus), A2 (with a translucent cumulus), B1 (with the corona radiata), B2 (partly...

OBJECTIVE To investigate the role of the cumulus cells and the cumulus matrix in affecting the penetrability, morphology, acrosome reaction, and motility of human spermatozoa penetrating the cumulus oophorus. DESIGN Controlled experimental laboratory study. SETTING University gynecology unit. PATIENT(S) Women undergoing assisted reproduction treatment and men visiting the subfertility cli...

Oocyte-derived bone morphogenetic protein 15 (BMP15) and growth differentiation factor 9 (GDF9) are key regulators of follicular development. Here we show that these factors control cumulus cell metabolism, particularly glycolysis and cholesterol biosynthesis before the preovulatory surge of luteinizing hormone. Transcripts encoding enzymes for cholesterol biosynthesis were downregulated in bot...

OBJECTIVE To determine whether the incidence of apoptosis in mature oocyte cumulus cells changes after insemination related to infertility. DESIGN Prospective study. SETTING Public hospital and university. PATIENT(S) One hundred women undergoing in vitro fertilization and embryo transfer (IVF-ET). INTERVENTION(S) Collection of cumulus cells from IVF-ET cycles with different infertility ...

BACKGROUND Bone morphogenetic protein-15 (BMP15) is a maternal gene necessary for mammalian reproduction. BMP15 expression increased in oocytes accompanied by follicle growth and development. The function and regulation mechanism of BMP15 in porcine cumulus cell apoptosis process is still unclear now. METHODS In this study, flow cytometry (FCM) was used to analyze the effects of BMP15 with di...

We investigated the ability of reactive oxygen species (ROS), such as hydrogen peroxide (H2O2), hydroxyl radical (OH), and hypochlorous acid (HOCl) to overcome the defensive capacity of cumulus cells, and elucidate the mechanism through which ROS differentially deteriorate oocyte quality. Metaphase II mouse oocytes with (n=1634) and without cumulus cells (n=1633) were treated with increasing co...

The serpin peptidase inhibitor, clade E, member 2 (SERPINE2) inhibits urokinase-type plasminogen activator (PLAU) and tissue-type plasminogen activator. Higher SERPINE2 expression levels were detected in cumulus cells of human immature oocytes than in those of mature oocytes. The objective of this study was to evaluate whether high SERPINE2 levels in cumulus cells are associated with oocyte imm...

During mammalian oocyte growth, genomic DNA may accumulate DNA double-strand breaks (DSBs) induced by factors such as reactive oxygen species. Recent evidence demonstrated that slight DSBs do not activate DNA damage checkpoint proteins in denuded oocytes. These oocytes, even with DNA DSBs, can resume meiosis and progress to metaphase of meiosis II. Meiotic resumption in oocytes is also controll...

Cumulus cells are a group of closely associated granulosa cells that surround and nourish oocytes. Previous studies have shown that cumulus cells contribute to oocyte maturation and fertilization through gap junction communication. However, it is not known how this gap junction signaling affects in vivo versus in vitro maturation of oocytes, and their subsequent fertilization and embryonic deve...