Cloning of novel temperature-related expressed sequence tags in rat testisduring spermatogenesis

Spermatogenesis needs the relatively cool environment of the scrotum in mos t mammals, it would be arrested when the testis was exposed to abdominal te mperature. In this study, we have used a differential display PCR technique (DD-PCR) to screen temperature-related ESTs during spermatogenesis (TRS) i n scrotal testes through a unilateral cryptorchid rat model after in situ a nalysis of testis cell DNA fragmentation. We reported here the cloning and sequencing of three such ESTs: TRS1, TRS3, and TRS4. Northern blot analysis confirmed that they were expressed specifically in scrotal testes. In situ hybridization showed that TRS1 was mainly expressed in the spermatocytes a nd the round spermatids in scrotal testis. Homology searches revealed that TRS1 and TRS3 were unknown cDNA sequences, and TRS4 was identical to a know n EST whose function had not been reported. TRS1, TRS2 and TRS3 were first found to be temperature-related during spermatogenesis. (C) 1999 Academic P ress.