FIG. 1.

Cdk2^−/− p53^−/− and Cdk2^−/− mice are sterile. (A) Representative photograph comparing testes from WT, Cdk2^−/− p53^−/−, Cdk2^−/−, and p53^−/− mice. The pictures indicate that testes of both Cdk2^−/− and Cdk2^−/− p53^−/− mice are smaller than WT testis. (B to D) Histology of testis sections indicates that the seminiferous tubules of Cdk2^−/− p53^−/− mice are atrophic like the ones from Cdk2^−/− mice. Bars, 40 μm.