retinoic acid improve germ cell differentiation from human embryonic stem cells

background: creation of artificial gametes may provide a universal solution for these patients of lacking gametes. stem cell technology may provide a way to obtain fully functional gametes. retinoic acid (ra) can initiate meiosis. several studies have demonstrated that ra can promote sperm cells differentiation from mouse embryonic stem cells (mescs) and other cells from human embryonic stem cells (hescs). objective: we sought to determine whether ra could promote differentiation of germ cells from hescs. materials and methods: hescs were differentiated as embryoid bodies (ebs) in suspension with all-trans ra (atra) or without atra for 0, 1, 3, 5 and 7 days, and then compared the expression of vasa, scp3, gdf9 and tekt1 by real-time pcr. the statistical differences were evaluated by one way anova. results: the expression of germ cell-specific markers including the gonocyte marker vasa, the meiotic marker scp3, and postmeiotic markers, gdf9 and tekt1, all increased in the presence and absence of ra as eb differentiation progressed. in addition, the expression of these markers increased an average of 9.3, 6.9, 7.2 and 11.8 fold respectively in the presence of ra, compared to the absence of ra, over 5 days differentiation. conclusion: our results indicate that hescs may have the potential to differentiate to primordial germ cells (pgcs) and early gametes. and ra can improve germ cells differentiation from hescs.