Expression of Hsp70-2 gene during germ cell apoptosis in rat unilateral cryptorchid testes

To investigate the role of Hsp70-2 gene in germ cell apoptosis induced by h eat stress, its expression changes were examined in rat normal and unilater al cryptorchid testes by using in situ hybridization, immunohistochemistry, and northern blot analysis techniques. The results showed that the express ion level of Hsp70-2 gene declined slightly at the early stage of germ cell apoptosis. and dropped dramatically when most of the germ cells were under going apoptosis on day 7.5 after the induction of cryptorchidism. This repo rt suggests for the first time that Hsp70-2 gene might not inhibit the apop tosis of germ cells at the early stage in cryptorchid testes. Hsp70-2 gene does not belong to the immediate early related genes that are responsible f or germ cell apoptosis induced by heat stress.