Histological analysis of cheetah testes focused on the germ cells and Sertoli cells

Understanding of relationship between physiological condition and testicular function in captive cheetahs would be beneficial for their successful breeding and conservation. This study investigated the states of germ cells and Sertoli cells in three captive cheetahs with different ages and health conditions using histological methods. The disarrangement of Sertoli cells and germ cells in seminiferous tubules was shown in all individuals. Many Sertoli cells detached from the basal membrane suggesting the decreased blood testis barrier. Spermatogenesis was observed in two cheetahs, whereas the number of elongated spermatids was lower than in domestic cats. One old cheetah with long-term health problem had no spermatids. These findings would be useful basic information for improving the reproduction of cheetahs in zoos.