THE DIFFERENTIATION OF MAMMALIAN OVARIAN GRANULOSA CELLS – LIVING IN THE SHADOW OF CELLULAR DEVELOPMENTAL CAPACITY

Abstract

The mammalian cumulus-oocyte complex (COCs) promotes oocyte growth and development duringlong stages of folliculogenesis and oogenesis. Before ovulation, the follicle is formed by a variety offully differentiated cell populations; cumulus cells (CCs) that tightly surround the female gamete,granulosa cells (GCs) and theca cells (TCs) which build the internal and external mass of the follicularwall. It is well documented that CCs surrounding the oocyte are necessary for resumption of meiosisand full maturation of the gamete. However, the role of the granulosa cells in acquisition of MII stageand/or full fertilization ability is not yet entirely known. In this article, we present an overview ofmammalian oocytes and their relationship to the surrounding cumulus and granulosa cells. We alsodescribe the processes of GCs differentiation and developmental capacity. Finally, we describe severalmarkers of mammalian GCs, which could be used for positive identification of isolated cells. Thedevelopmental capacity of oocytes and surrounding somatic cells – a “fingerprint” of folliculogenesisand oogenesis