Figure 4. Dose-dependent decrease or increase of the number of germ cell (VASA, DAZL) and of γH2AX positive cells, respectively, in nicotine treated fetal ovaries cultured for 4 days. (A) Representative IF images of ovarian tissue sections for VASA and γH2AX; note that only a subset of the γH2AX positive cells were also VASA positive (arrow heads); (B) Representative IF images of ovarian tissue sections for DAZL; (C) Relative percentage of VASA and DAZL positive cells of ovaries cultured without (control) and with 1mM or 10mM nicotine. All experiments were repeated at least three times. (*) and (**) indicate significant (P < 0.05) and highly significant (P < 0.01) difference, respectively.