A physiological approach for supporting oocyte-cumulus cell communication and chromatin remodelling at meiotic resumption

In vitro embryo production (IVP) remains inefficient in both clinical applications of human reproduction and animal breeding and the development of pre-maturation strategies to improve IVP is a mayor challenge in assisted reproductive technologies. The diversity of oocyte competences is mainly due to the intrinsic heterogeneity of the cohort of follicles from which cumulus-oocyte complexes to be subjected to standard IVP procedures are isolated. In particular, the precocious meiotic resumption that occurs when oocytes are isolated from the follicles is the main factor that impairs oocyte ability to become an embryo in vitro. Here are presented a series of studies on physiological approaches to pre-maturation system in order to develop the suitable conditions for in vitro maturation that support high quality oocyte production. The large-scale chromatin remodeling process that occurs in the germinal vesicle has been considered as a specific hallmark of the progressive meiotic and developmental competencies acquisition during the final stages of oocyte differentiation in order to obtain high quality egg in vitro.