FIG. 3.

Benzo[a]pyrene (BaP)-mediated germ cell death in fetal ovaries requires caspase activation. Germ cells were counted as described in Materials and Methods section in 13.5 dpc ovaries cultured for 48 h with 0.005% DMSO alone, 50 μM of z-VAD-fmk pretreatment followed by control media, 1000 ng/ml of BaP alone, or z-VAD-fmk pretreatment followed by BaP. A, Mean ± SEM total number of germ cells per ovary. Representative images of germ cells identified by TRA98 immunodetection in fetal ovaries cultured with z-VAD-fmk (B); 1000 ng/ml BaP (C); z-VAD-fmk and 1000 ng/ml BaP cotreatment (D). n = 6–7/group. Scale bars, 100 µm. *P < .05 compared with vehicle and z-VAD-fmk control. UC, uncultured (0 h).