Abstract: Objective To investigate the role of Histone Methyltransferase EZH2 when mouse induced pluripotent stem (iPS) cell line IP14D-1 differentiates into primordial germ cells(PGCs) in vitro. Methods IP14D-1-derived EBS were maintained in culture medium containing 1μM atRA for 2d, 4d and 7d, respectively. RT-PCR、Western blot and immunofluorescence were performed to detect the expression changes of Ezh2 and Stra8 in the atRA processing IP14D-1-EBs around. Results The expression features of genes showed that Ezh2 mRNA rapidly reached peak value in 2d, and with the induction of prolonged expression decreased; In contrast, Stra8 expression increased when the EBs induced with atRA to extend. Immunofluorescence showed positive signals of Ezh2 and Stra8 were located on the membrane and in the cytoplasm, this result was consistent with the RT-PCR. Conclusions The EZH2 appeares earlier in IP14D-1-derived EBS and is due to the induction of the atRA, and the expression of Ezh2 and Stra8 is not coordinated. Low expression of EZH2 may occur earlier in the differentiation of PGCs with atRA introduction, the enhanced expression of Stra8 may start the differentiation of IP14D-1 to the germ cell.

Key words: mouse induced pluripotent stem cells, germ cells, EZH2, atRA