Follicle-stimulating hormone (FSH) and oocyte-secreted factors influence granulosa cell differentiation and follicle development. Whereas FSH stimulates the expression of mural cell transcripts, oocyte-secreted factors regulate specific cumulus cell genes and suppress the appearance of mural cell transcripts. This study addresses the extent to which clinically relevant changes in FSH doses appl...

STUDY QUESTION Does maternal ageing and ovarian stimulation alter mitochondrial DNA (mtDNA) copy number and gene expression of oocytes and cumulus cells from a novel bovine model for human IVF? SUMMARY ANSWER Oocytes collected from females with identical nuclear genetics show decreased mtDNA copy number and increased expression of an endoplasmic reticulum (ER) stress gene with repect to ovari...

In the present study we examined whether LPA can be synthesized and act during in vitro maturation of bovine cumulus oocyte complexes (COCs). We found transcription of genes coding for enzymes of LPA synthesis pathway (ATX and PLA2) and of LPA receptors (LPAR 1-4) in bovine oocytes and cumulus cells, following in vitro maturation. COCs were matured in vitro in presence or absence of LPA (10(-5)...

Background: The maturation medium for in-vitro oocyte maturation is usually supplemented with serum. However, supplementation of serum from pregnant women adversely affects the outcome of in-vitro maturation. The purpose of the study was to assess if growth factors or granulosa cell coculture could overcome the adverse effects of pregnant women’s serum. Materials and Methods: The basal maturati...

This study was conducted to investigate the effects of Trichostatin A (TSA) on cumulus expansion during mouse oocyte maturation. TSA treatment inhibited cumulus expansion and significantly reduced the cumulus expansion index (CEI) (p<0.05). To determine the underlying mechanism, the expression levels of several key factors that play crucial roles in cumulus expansion including components of ext...

This study was designed to examine the effects of retinoic acid adding to cumulus and/or fibroblast cellsmonolayer on the development of mouse early embryos. One-cell mouse embryos were obtained from NMRImice after superovulation by an intraperitoneal injection of 5 IU equine chorionic gonadotrophin (eCG)followed 48 hrs later by 5 IU human chorionic gonadotrophin (hCG). Mouse embryonic fibrobla...

Background: Fertilization is a multistep process requiring spermatozoa with unique cellular structures and numerous germ cell-specific molecules that function in the various steps. In the highly coordinated process of male germ cell development, RNA splicing and polyadenylation help regulate gene expression to ensure formation of functional spermatozoa. Male germ cells express tauCstF-64 (Cstf2...

Oocytes and their companion somatic cells maintain a close association throughout oogenesis and this association is essential for normal oocyte and follicular developmenL This review summarizes current concepts of the role of the somatic cells in the regulation of mammalian oocyte growth, the maintenance of meiotic arrest, the induction of oocyte maturation, and the acquisition of full embryoni...

During follicular atresia in the sheep and pig there is a marked reduction in the vasculature of the theca interna underlying the membrana granulosa. In the sheep there is no reduction of thecal blood vessels adjacent to the cumulus which remains viable. By contrast, in the pig the cumulus degenerates during atresia and the underlying thecal vasculature is greatly diminished. However, despite l...

Cell-secreted vesicles, such as exosomes, have recently been recognized as mediators of cell communication. A recent study in cattle showed the involvement of exosome-like vesicles in the control of cumulus expansion, a prerequisite process for normal ovulation; however, whether this is the case in other mammalian species is not known. Therefore, this study aimed to examine the presence of exos...