Research Paper Volume 12, Issue 8 pp 7313—7333

Estrogen regulation of germline stem cell differentiation as a mechanism contributing to female reproductive aging

Figure 8. Enhancement of OSC differentiation by RA requires repression of DNA methyltransferase activity. (A, B) Levels of Stra8 mRNA (A) and numbers of IVD-oocytes generated (B) in cultures of OSCs treated with vehicle (V), E2 (10 nM) or RA (2 μM) for 8 hours (mean ± SEM, n = 3 independent cultures; *P<0.05). (C) Levels of CD38 mRNA in OSCs cultured with vehicle (V), E2 (10 nM) or RA (2 μM) for 8 hours (mean ± SEM, n = 3 independent cultures; *P<0.05). (D) In-silico analysis of the Stra8 genomic sequence (transcription start site indicated by arrowhead), identifying a CpG island spanning 386-bp (highlighted by the yellow bar). (E, F) Levels of Stra8 mRNA (E) and numbers of IVD-oocytes generated (F) in cultures of OSCs treated without or with 2-μM RA for 8 hours after a 4-hour pretreatment without or with 50-μM EGCG (–, without; +, with) (mean ± SEM, n = 6 independent cultures; **P<0.01).