Figure 2. Dose-dependent nicotine induction of apoptosis in fetal ovaries cultured for 4 days. (A) Ovaries cultured without (control) and with 1 mM or 10 mM nicotine; note altered ovary morphology at 10mM nicotine and representative H&E histological sections of the ovaries; (B) IF for Caspase3 and ɤH2AX in tissue sections of ovaries cultured without (control) and with 1mM or 10mM nicotine; (C) Relative percentage of Caspase3 and ɤH2AX positive cells in ovaries cultured without (control) and with 1mM or 10mM nicotine; (D) Bax/Bcl2 mRNA ratio in samples extracts from ovaries cultured without (control) and with 1mM or 10mM nicotine. The expression level was normalized to that of Gapdh. (E) Increased BAX/BCL2 protein ratio in nicotine exposed ovaries in comparison with control. All experiments were repeated at least three times. Changes are presented as mean ± SD. (*) and (**) indicate significant (P < 0.05) and highly significant (P < 0.01) difference, respectively.