Environmental influences on the testis cycles of the lizards Dipsosaurus dorsalis and Xantusia vigilis

1. 1. Annual testis cycles in the lizards Dipsosaurus dorsalis and Xantusia vigilis are regulated by both exogenous, especially thermal, stimuli and an endogenous rhythmicity. 2. 2. High temperatures appear to be the primary cue for stimulating spermatogenesis and androgenesis in spring. 3. 3. Photoperiod affects X. vigilis in mid-winter (long days stimulate the testes), but only at high body temperatures, and photoperiodic sensitivity is lost by March. 4. 4. Testis regression appears to be essentially independent of photoperiod and temperature in both lizards, and an endogenous rhythm is postulated. 5. 5. A prolonged, post-nuptial, sexual refractory period accounts for the suppression of spermatogenic activity...

Categories: Publication; Types: Citation, Journal Citation; Tags: Comparative Biochemistry and Physiology, Dipsosaurus dorsalis, Testis cycle, Xantusia vigilis, gonadotropin, All tags... lizard, photoperiodism, pituitary-testis axis, reproductive cycle, spermatogenesis, temperature, testis, Fewer tags