Effects of Treatment with Bone Morphogenetic Protein 4 and Co-culture on Expression of Piwil2 Gene in Mouse Differentiated Embryonic Stem Cells

Background: Specific growth factors and feeder layers seem to have important roles in in vitro embryonic stem cells (ESCs) differentiation. In this study,the effects of bone morphogenetic protein 4 (BMP4) and mouse embryonic fibroblasts (MEFs) co-culture system on germ cell differentiation from mouse ESCs were studied. Materials and Methods: Cell suspension was prepared from one-day-old embryoid body (EB) and cultured for four days in DMEM medium containing 20% fetal bovine serum (FBS) in the following groups: simple culture (SC), simple culture with BMP4 (SCB), co-culture (CO-C) and co-culture with BMP4 (CO-CB). Expression of piwi-like homolog 2 (Piwil2), the germ cell-specific gene, was evaluated in the different study groups by using quantitative real time polymerase chain reaction (RT-PCR). Testis was used as a positive control. Results: The maximum and minimum Piwil2 expression was observed in SC and SCB groups, respectively. A significant difference was observed in Piwil2 expression between SCB and other study groups (p < 0.05). Conclusion: The findings of this study showed that neither the addition of BMP4 in culture medium nor the use of MEFs as a feeder layer have a positive effect on late germ cell induction from mouse ESCs.