Temperature Effects on the Kinetics of Spermatogenesis in the Mouse

The kinetics of spermatocyte differentiation in adult mice was measured under normal conditions, during maintenance at elevated temperatures and following experimental cryptorchidism. For these measurements the development of 3 H‐TdR labelled testis cells was followed by velocity sedimentation at unit gravity and the results were in agreement with those obtained by autoradiography. In the cryptorchid animals and those maintained at 32°C the kinetics of spermatogenesis during treatment was increased by at least 13% over control values. Smaller but significant increases in the kinetics of spermatogenesis were obtained at ambient temperatures of 28 and 30°C without any observable histological damage. The increased kinetics is believed to be a direct effect of temperature on testis cell development.