Fertility depends on the precise coordination of multiple events within the ovarian follicle to ensure ovulation of a fertilizable egg. FSH promotes late follicular development, including expression of luteinizing hormone (LH) receptor by the granulosa cells. Expression of its receptor permits the subsequent LH surge to trigger the release of ligands that activate EGF receptors (EGFR) on the gr...

Information about the mechanisms of meiotic arrest and resumption of meiosis in feline oocytes is still limited. The aim of this study was to investigate the effect of the presence of gonadotropins during IVM, on meiotic progression in relation to the status of gap junction mediated communications between oocyte and cumulus cells, to the cAMP intracellular content, and to the intra-oocyte conce...

Somatic cell nuclear transfer is a complex and intricate procedure with a low success rate. Despite advances in embryo culture and the production of specialized tools and equipment success rate has remained poor. The procedure remains basically the same despite technical innovations but is now easier to learn and requires less technical expertise. Oocytes now come from an in vitro system, which...

Polycystic ovary syndrome (PCOS) is a common frequent endocrine disorder among women of reproductive age. Although assisted reproductive techniques (ARTs) are used to address subfertility in PCOS women, their effectiveness is not clear. Our aim was to compare transcriptomic profiles of oocytes and cumulus cells (CCs) between women with and without PCOS, and assess the effectiveness of ARTs in t...

2012 School of Biological Science 2 Acknowledgements I would like to acknowledge, with appreciation, everyone who has contributed to this research. Firstly I would like to thank my primary supervisor Professor Ken McNatty for making it possible for me to do this research and for his patience and understanding in the face of some dumb moments on my part. I couldn't have completed this without hi...

BACKGROUND A limitation to our ability to distinguish between developmentally competent and incompetent eggs is our still only partial knowledge of the critical features that are needed to make a good egg and when during oogenesis these specific characteristics are acquired. The main objective of this review is to summarize the results of areas of investigation that are contributing to our stil...

Mammalian oocytes grow and undergo meiosis within ovarian follicles. Oocytes are arrested at the first meiotic prophase, held in meiotic arrest by the surrounding follicle cells until a surge of LH from the pituitary stimulates the immature oocyte to resume meiosis. Meiotic arrest depends on a high level of cAMP within the oocyte. This cAMP is generated by the oocyte, through the stimulation of...

Empty follicle syndrome (EFS) is a condition in which no oocytes are obtained after an apparently successful ovarian stimulation. Genuine EFS (GEFS) is differentiated from false EFS by an optimal level of human chorionic gonadotropin on the day of oocyte retrieval. Some believe that GEFS does not exist and that it is only a reflection of the margin of error attendant upon the procedure of oocyt...

Fertilization involves several precisely coordinated steps, including sperm dispersal of the oocyte cumulus mass, adhesion and binding to the zona pellucida, penetration through the zona pellucida, and fusion with the oocyte. Hyaluronidase, which is present in the sperm head, is known to be essential for the decomposition of the oocyte cumulus mass. Interestingly, two types of hyaluronidase—SPA...

BACKGROUND MicroRNA (miRNA) are small non-coding RNA molecules critical for regulating cellular function, and are abundant in the maturing oocyte and developing embryo. MiRNA-21 (MIR21) has been shown to elicit posttranscriptional gene regulation in several tissues associated with rapid cell proliferation in addition to demonstrating anti-apoptotic features through interactions with PDCD4 mRNA ...