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 ...

Background: In vitro maturation is a good method to decrease cancer risk of superovulation by gonadotropin hormones. A paracrine effect of oocyte secretions on oocyte developmental competence is under investigation. Apart from oocyte maturation, ovulation in vivo requires a precise control of extracellular matrix modification. Cumulus cells secrete hyaluronan to form a muco-elastic extracellula...

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 ...

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...

Background: Omega-3 fatty acids can modify gene and protein expression through altering the function of transcription factors controlling gene expression. Cumulus expansion, is a critical process for normal oocyte development, ovulation, and fertilization. This event needs to the synthesis of hyaluronic acid and its production is controlled by the enzyme hyaluronic acid synthase 2 (HAS2). The a...

This study aimed to determine the influence of cyclic guanosine 3'5'-monophosphate (cGMP) and cGMP-dependent kinase (PKG) during in vitro maturation (IVM) on lipolysis-related parameters in bovine cumulus-oocyte complexes (COCs), and on embryo development and cryosurvival. COCs were matured with cGMP/PKG modulators and assessed for metaphase II rates (MII), cGMP levels, lipid content in oocytes...

Mammalian oocytes are surrounded by numerous layers of cumulus cells, and the loss of gap junctional communication in the outer layers of cumulus cells induces meiotic resumption in oocytes. In this study, we investigated the dynamic changes in the gap junctional protein connexin-43 in cumulus cells during the meiotic resumption of porcine oocytes. The amount of connexin-43 in all layers of cum...

BACKGROUND In this review, recent advances in the laboratory as well as embryological aspects of hCG priming in vitro maturation (IVM) cycles are described. METHODS This report is based on publications from literature searches and the authors' experience. RESULTS In IVM cycles, priming with hCG permits the recovery of a certain number of oocytes with an expanding/dispersed cumulus pattern w...

(SCNT) embryos of buffaloes. 2. To study gene expression profile of important developmental genes at different stages of SCNT cloned embryo. 3. To study epigenetic reprogramming during early developments of SCNT embryos Materials and Methods: Expression analysis of developmental genes was done in different (ovarian granulose and cumulus and skin fibroblasts) donor cells; in vitro maturing oocyt...

Oocyte quality is a key limiting factor in female fertility, yet we have a poor understanding of what constitutes oocyte quality or the mechanisms governing it. The ovarian follicular microenvironment and maternal signals, mediated primarily through granulosa cells (GCs) and cumulus cells (CCs), are responsible for nurturing oocyte growth, development and the gradual acquisition of oocyte devel...