Fig. 1. Postnatal Pin1^-/- males and females have fewer germ cells. (A,C,E,G) Wild-type; (B,D,F,H) Pin1^-/-. (A,B) Adult testis section shows that Pin1^-/- testis has mostly empty seminiferous tubules containing only Sertoli cells and no germ cells. (C,D) Adult ovary section reveals that few ovarian follicles are seen in Pin1^-/- females. (E,F) Newborn testis section shows that Pin1^-/- testis has many fewer gonocytes, identified by the GCNA1 antigen (brown), within properly formed testis cords, while many gonocytes populate the wild-type testis. (G,H) Numerous oocytes, highlighted by the blue circles, are in a newborn wild-type ovary. The newborn Pin1^-/- ovary has few oocytes. (A,B) Periodic acid-Schiff histochemistry. (C,D,G,H) Hematoxylin and Eosin. (E,F) Immunohistochemistry with antibodies to GCNA1.