Figure 7. Dose-dependent nicotine decrease of mRNAs of germ cell specific and meiotic genes in fetal ovaries cultured for 4 days evaluated by qRT-PCR. The expression level was normalized to that of Gapdh gene. All experiments were repeated at least three times. Results are presented as mean ± SD. (*) and (**) indicate significant (P < 0.05) and highly significant (P < 0.01) difference, respectively.