The Insight into Developmental Capacity of Mammalian Cocs and Cumulus-Granulosa Cells-Recent Studies and Perspectives

The mammalian oocyte maintains in the follicular environment that significantly influences its ability to growth and development. The complex process of mammalian oocytes development involves stages of gamete nuclear and cytoplasmic maturation, which finally must lead to formation of a fully mature female gamete ready for successful monospermic fertilization. Although there are a lot of studies indicating the role of the oocyte status on the embryo development in the Preimplantation stage, there are still no data related to gamete-surrounding somatic cells, called Cumulus oophorus (CCs) and follicular Granulosa Cells (GCs). Moreover, the role of surrounding CCs and/or GCs is in many cases discriminated during the routine procedure of in vitro Fertilization (IVF). The application of GCs primary culture, soon after their recovery from preantral follicles, is highly related to the increasing proliferation index, which is correlated with further GCs changed into Luteal Cells (LC). Luteinization of GCs may be recognized as the cellular potency of these cells and is associated with expression of specific markers such as Vanin-2 (VNN2), Regulator of G protein Signaling-2 (RGS2), Pentraxin-3 (PTX3), and Prostaglandin-endoperoxide Synthase-2 (PTGS2). Therefore, this review demonstrated the present knowledge regarding biology of somatic cells that surrounds oocytes (CCs and GCs) during their growth in oogenesis as well as highlighting the possible further use of these both cells populations in reproductive diagnostics and assisted reproductive techniques.