Figure 7.

Immunohistochemical staining of sectioned adult mouse testes with anti-proliferating cell nuclear antigen antibody to detect proliferating cells. In the Dazl^−/− mouse a proportion of tubules appears devoid of proliferating germ cells, and the remainder contain only peripherally located, premeiotic spermatogonial stages (c and d, arrowheads). The Dazl^−/−;TgS12 transgenic mouse exhibits a pronounced increase in the spermatogonial population and the presence of numerous prophase spermatocytes (arrows) in the tubular lumen, indicating partial restoration of meiosis (a and b). The Dazl^−/−;TgS12 and control Dazl^−/− mice were derived from the same cross of Dazl^Tm1Hgu/+;TgS12 × Dazl^Tm1Hgu/+;TgS12 animals. The individual animals are identified as a and b (Dazl^−/−;TgS12) and c and d (Dazl^−/−) in Fig. 8.