Oocyte competence: importance and determinant factors in vivo and in vitro

Reproductive biotechnology promoted beef cattle production growth in the global agribusiness scenario due to the reduction of generation interval, accelerated genetic gain and productivity enhancement. In this context, however, there are biological and physiological challenges that, despite scientific and biotechnological advances, have not yet been overcome. Superovulation associated with follicular aspiration and in vitro production of embryos from cumulus-oocyte complexes (COCs) that would ultimately develop atresia, have its efficiency limited, basically, by oocyte quality, which is directly related to oocyte competence to complete its capacitation, represented by nuclear and cytoplasmic maturation, as well as supporting the fertilization and initial embryogenesis. This process of oocyte capacitation, both in vivo and in vitro determines, therefore, the embryo development potential and involves a complex interaction of regulatory molecules in addition to molecular and structural changes, which are still under the influence of intra and extra-ovarian factors. Thus, given the importance of the oocyte for female fertility, the present review aims to discuss the main aspects involved in oocyte capacitation, its interfering factors, and to present possible selection methods of competent COCs.