Impaired oocyte quality has been demonstrated in diabetic mice; however, the potential pathways by which maternal diabetes exerts its effects on the oocyte are poorly understood. Cumulus cells are in direct contact with the oocyte via gap junctions and provide essential nutrients to support oocyte development. In this study, we investigated the effects of maternal diabetes on the mitochondrial ...

This study assessed the participation of amphiregulin (AREG) and bone morphogenetic protein 15 (BMP15) during maturation of bovine cumulus-oocyte complexes (COCs) on cumulus cell function and their impact on subsequent embryo development. AREG treatment of COCs enhanced blastocyst formation and quality only when in the presence of BMP15. Expression of hyaluronan synthase 2 was enhanced by folli...

MicroRNA-378 regulates oocyte maturation via the suppression of aromatase in porcine 1 cumulus cells 2 Bo Pan, Derek Toms, Wei Shen, Julang Li 3 Department of Animal and Poultry Science, University of Guelph, Guelph, Ontario 4 Laboratory of Germ Cell Biology, College of Animal Science and Technology, Qingdao 5 Agricultural University, Qingdao, China 6 7 Abbreviated title: Cumulus cell miR-378 i...

The aim of the study was to evaluate the effects of follicle stimulating hormone (FSH), luteinizing hormone (LH), epidermal growth factor (EGF) and estradiol 17-β (E2) in maturation medium on nuclear maturation and cumulus expansion of cumulus-oocyte complexes (COCs) obtained from bovine ovaries. COCs were classified as good and poor quality grades based on cumulus investment. COCs were then su...

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...

The musk shrew, Suncus murinus, is an induced ovulator, the cumulus oophorus of which is unusual in several respects: it has no matrix, it always induces the acrosome reaction and it appears to be essential for fertilization. The present study documents distinctive features of the cumulus oophorus before and after ovulation, and of copulation-induced maturation of the ovulatory follicle, which ...

This study investigated the participation of MAPK in the resumption of meiosis [germinal vesicle breakdown (GVB)] in oocytes and cumulus expansion using oocyte-cumulus cell complexes (OCC) from Mos-null mice (Mos(tm1Ev)/Mos(tm1Ev), hereafter Mos(-/-)). MAPK activity was not detected in Mos(-/-) oocytes whether they matured in vivo or in vitro, with or without gonadotropin stimulation. Therefore...

BACKGROUND The understanding of the mechanisms regulating human oocyte maturation is still rudimentary. We have identified transcripts differentially expressed between immature and mature oocytes and cumulus cells. METHODS Using oligonucleotide microarrays, genome-wide gene expression was studied in pooled immature and mature oocytes or cumulus cells from patients who underwent IVF. RESULTS...

The cryopreservation of female gametes is still an open problem because of their structural sensitivity to the cooling-and-freezing process and to the exposure to cryoprotectants. The present work was aimed to study the effect of vitrification on immature bovine oocytes freed of cumulus cell investment before freezing. To verify the feasibility and efficiency of denuded oocyte (DO) cryopreserva...