Fig. 4

Zar1 deficiency causing all-male phenotype is due to p53-mediated apoptosis. (A-C) TUNEL staining of ovary sections of zar1 homozygotes and control siblings at 37-40 dpf. Obvious apoptotic cells are observed in immature ovaries in zar1 homozygotes (A), but not in sibling controls (B). Quantification of apoptotic cells is shown in C; 18 sections from 6 juveniles were counted for each genotype. (D) Gender analysis of zar1^−/− homozygotes on different p53 genotype backgrounds (p53^+/+, p53^+/− and p53^−/−). Females are only observed in p53^−/−;zar1^−/− double homozygous mutants. (E,F) H&E staining of sections of p53^−/−;zar1^+/− and p53^−/−;zar1^−/− adult ovaries. p53^−/−;zar1^−/− ovaries are morphologically normal. (G-J) TUNEL staining of ovary sections of p53^−/−;zar1^−/− ovaries at 37-40 dpf with p53^−/−;zar1^+/− and p53^+/−;zar1^−/− ovaries as controls. (J) Quantification of apoptotic cells. Nine sections from three juveniles were counted for each genotype. Scale bar: 20 μm.