Testicular development and maturation of the hypothalamic-pituitary-testicular axis in the male tammar, Macropus eugenii

Abstract

Testicular growth and maturation of the hypothalamic-pituitary-testicular axis were assessed in male tammars from 12 to 25 months of age to establish the time of sexual maturity. The testicular dimensions and body weights of 20 male tammars, ~ 12 months of age at the beginning of the study, were measured monthly for 1 year. Groups of 3 animals were castrated at 13, 19 and 25 months of age and their testes sectioned for histological examination. Testicular volume increased between 12 and 24 months of age and was highly correlated with body weight (r = 0.91). In the first 13-month group the seminiferous tubules were closed with few mitotic figures. Spermatogenesis had begun in 2 of the 19-mont..