EXPERIMENTAL CRYPTORCHIDISM INDUCES TESTICULAR GERM-CELL APOPTOSIS BYP53-DEPENDENT AND P53-INDEPENDENT PATHWAYS IN MICE

Cryptorchidism is associated with male infertility: germ cell loss occ urs by apoptosis in response to elevated temperature, Since the tumor suppressor p53 is highly expressed in the testis and is known to induc e apoptosis, an investigation was undertaken to establish whether heat stress causes p53-mediated germ cell apoptosis, Using a mouse model o f experimental unilateral cryptorchidism, it was observed that testicu lar weight reduction, germ cell loss, and DNA fragmentation all began in the crypt-orchid testes on Day 6-7 in wild-type mice, In contrast; these changes were delayed by 3 days In p53-/-mice, These results sugg est that abdominal heat stress induces germ cell toss through two apop totic pathways: a p53-dependent pathway responsible for the initial ph ase of germ cell apoptosis, and a p53-independent pathway that account s for subsequent apoptosis.