The addition of alpha-amanitin to extrafollicular, cumulus-enclosed ovine oocytes at explantation inhibits meiotic maturation and prevents many of the changes in protein synthesis that normally accompany maturation. By contrast, these inhibitory effects are considerably reduced by either delaying the addition of the drug for 1-4 h or by denuding the oocytes of all associated cumulus cells at th...

Oocyte maturation is a key issue of current animal biotechnology. This study was designed to examine the morphodynamics of the cumulus-oocyte association during oocyte maturation. Porcine cumulus-oocyte complexes were recovered from slaughterhouse ovaries; matured in vitro for 0, 24, 36, and 44 h; and evaluated by scanning electron microscopy either combined or not combined with the osmium-dime...

The cumulus-oocyte complex (COC) is an oocyte surrounded by specialized granulosa cells, called cumulus cells. cells surrounding the ensure healthy and embryo development. maturity of COCs at retrieval may be used as indicator to predict outcome assisted reproductive technology (ART). Segmenting a preliminary step in many image processing pipelines evaluate maturity. However, acquiring well-ann...

Background: For several years, mammalian cloning by splitting an early embryo or nuclear transfer into oocytes method has been successfully performed. Cloning is now also possible using adult somatic cells. Although it has now been 15 years since the first cloned mammals were generated from somatic cells using nuclear transfer (NT), the success rate for producing live offspring by cloning is lo...

Background: The hyaluronidases are the enzymes hydrolyze β-1, 4 glycosidic linkage of hyaluronan. Hyaluronan is a polymer consisting of a repeating disaccharide unit found in cumulus ovuforus complex, semen liquid and other tissue. Addition to hydrolyzing the hyaluronan, hyaluronidase can penetrate through the cumulus cells layer that surrounds the oocyte, thus it terms spreading factor. Moreov...

Most studies have considered the negative influence of obesity on fertility in both genders. In the present study, we assessed mitochondrial activity expressed as the mitochondrial potential index (MPI) in cumulus cells from obese women and women with a normal body mass index (BMI) during assisted reproductive therapy. The results revealed a significant reduction of MPI with increased body mass...

BACKGROUND Serum AMH is declining with age and is highly associated with ovarian follicular reserve and disordered folliculogenesis. However, the precise role of AMH in the process of human follicular aging has still to be determined. AIM This study investigates AMH level in the follicular fluid (FF) and mRNA expression pattern in cumulus and mural granulosa cells of human ovarian follicles i...

BACKGROUND Polycystic ovary syndrome (PCOS) is a common endocrine and metabolic disorder in women. The developmental competence of oocytes and embryos in PCOS patients is reduced to a certain extent (comparing to non-PCOS patients, the high quality embryo rate was decreased by 16% from the data of our centre) during the in vitro fertilization (IVF) process. Cross-talk between the oocyte and cum...

BACKGROUND The gonadotropin-induced resumption of oocyte meiosis in preovulatory follicles is preceded by expression of epidermal growth factor (EGF)-like peptides, amphiregulin (AREG) and epiregulin (EREG), in mural granulosa and cumulus cells. Both the gonadotropins and the EGF-like peptides possess the capacity to stimulate resumption of oocyte meiosis in vitro via activation of a broad sign...

Acquisition of oocyte developmental competence needs to be understood to improve clinical outcomes of assisted reproduction. The stimulation of cumulus cell concentration of cyclic adenosine 3'5'-monophosphate (cAMP) by pharmacological agents during in vitro maturation (IVM) participates in improvement of oocyte quality. However, precise coordination and downstream targets of cAMP signaling in ...