Review: The regulation of meiotic maturation in bovine oocytes

Abstract

Meiotic maturation in mammalian oocytes is initiated during fetal development, arrested for several years in some cases, then completed at the time of ovulation. Although the mechanisms involved in oocyte meiotic arrest and meiotic resumption are not fully understood, new players and roles have recently been identified. This paper reviews the role of follicle cells, as well as the role of the cyclic adenosine 3', 5'-monophosphate (cAMP) pathway, in the maintenance of meiotic arrest. Potential mechanisms by which luteinizing hormone (LH) signals meiotic resumption are also reviewed. New findings on the role of adenosine monophosphate-activated kinase (PRKA), as well as the effects of culture medium composition on meiosis in vitro, are also discussed. From a practical perspective, improved understanding of the mechanisms involved in the control of meiosis will facilitate better control of the process in vitro resulting in increased developmental competence and increased efficiency of in vitro embryo production procedures. Key words: Bovine, oocyte, meiosis, cAMP