earticle

영어

Mammalian testes are maintained at a lower temperature than the abdominal region for healthy spermatogenesis. Germ cell apoptosis has been described in heat-damaged testes by cryptorchidism, but the mechanism is not yet fully understood. To elucidate the cause of germ-cell death by cryptorchidism, we surgically induced cryptorchidism in dog testes and performed histological and molecular analyses. Histological data showed that the seminiferous tubules of cryptorchid testes and epididymis contained significantly fewer germ cells. Total RNA sequencing was performed to screen overexpressed genes in cryptorchid dog testes. Clusterin RNA was significantly higher (approximately 12.8-fold) in cryptorchid testes than in normal testes. In addition, cleaved caspase-3 and -8 were detected at higher levels in cryptorchid dog testes. Real time RT-PCR and western blotting analysis showed that the expression of clusterin was higher in cryptorchid dog testes. Furthermore, clusterin was detected in extracellular regions of cryptorchid dog testes during 4 weeks after surgery. Thus, we demonstrated germ-cell specific apoptosis and expression of clusterin in extracellular regions of cryptorchid dog testes. This result will facilitate further study of spermatogenesis and the specific mechanisms by which cryptorchidism causes male infertility.