Bmp4 exposure increases expression of meiotic markers during differentiation of germ cells from mouse embryonic stem cells

Headnote

Key words: Germ cells, Embryonic stem cells, Bone morphogenetic protein 4, Embryoid body.

P-113

Introduction: Adding bone morphogenetic protein 4 (BMP4) to the culture media of embryonic stem (ES) cells has been proposed to induce germ cell differentiation. Obviously, first step in gamete production depends on the induction of the meiosis.In the current study, we investigated the induction of germ cell meiosis by BMP4 exposure.

Materials and Methods: Embryonic stem cells were propagated on a feeder layer of mouse embryonic fibroblastsin ES cell medium supplemented with LIF. Then, the ES cells were detached from feeder and differentiated through embryoid body(EB) and monolayer culture system in LIF-free ES cell media in presence or absence of BMP4 for 5 days.Using quantitative real-time RT-PCR, a subset of meiotic markers, Stra8, SCP1, SCP3, and REC8, were assessed following treatment the cells with (+BMP4) or without BMP4 (-BMP4).

Results: Expression of the meiotic markers significantly increased after treatment with BMP4 in EB differentiation protocol. In monolayer culture system, a significant reduction in mRNA levels of SCP1, SCP1, and REC8 was observed in +BMP4 cultures after 5 days compared with the cells cultured in -BMP4 condition . In contrast, the presence of BMP4 in the culture media of monolayer culture condition did not impact on the Stra8 gene expression level.

Conclusion: Expression of meiotic genes following treatment with BMP4 enhanced in EB formation protocol; however, it was not affected in monolayer culture system. Overexpression of meiotic markers that has been shown in this study, could suggest promoting ES cell differentiation to post-migratory germ cells.