Autonomous testicular hormonal control of fetal gubernaculum development in rabbits: a re-examination of histological slides in the legacy of the late Professor Alfred Jost.

The present study investigated whether the male differentiation of the gubernacular primordia depends on fetal pituitary control. Therefore, gubernaculum development was analysed in the same histological preparations that the late Professor Alfred Jost had used to examine the effects of fetal decapitation on the other parts of the developing genitalia. Decapitation had taken place at the onset of sexual differentiation (day 19 after conception) and the results examined just before the expected birth (day 28 after conception). Fetal decapitation had no noticeable effect on the development of these large and complex male-specific structures. It was concluded (1) that fetal control of male gubernaculum development operates through a mechanism different from that involved in male differentiation of the other component parts of the genitalia and (2) that this mechanism is not under fetal pituitary control. The results thus provide further support for the existence of a separate fetal hormone to bring about male differentiation of the gubernacular primordia.