Derivation of oocyte-like cells from mouse embryonic stem cells

In vitro derivation of oocytes from mouse embryonic stem cells (ESCs) would benefit the study of oogenesis. Here, we induced mouse ESCs to differentiate into oocyte-like cells by culturing adherent embryoid bodies (EBs) in different medium, including retinoic acid (RA) and follicular fluid. The extent of differentiation was evaluated through morphology and the expression of certain specific germ cell markers such as Oct4, Vasa, Scp3, Zp3, Gdf9 and Figla. As a result, EBs developed into ovary-like structures that contained oocyte-like cells showing expression of Oct4, Vasa, Gdf9, Figla and meiotic specific gene Scp3 and oocyte marker-Zp3. This study shows that RA and follicular fluid are beneficial for the derivation of germ cells and oocyte-like cells from mouse ES cells. The derivation of oocyte-like cells by our method offers an approach for studying oogenesis and regulation mechanism of mouse ESCs differentiation.