What Animal Models of Testicular Descent and Germ Cell Maturation Tell Us about the Mechanism in Humans.

Testicular descent occurs in most mammals in two main steps that have different hormonal control and anatomical processes. The evolution of testicular descent reveals the same basic processes in humans and animals, with minor differences in timing and anatomy, especially the location of the scrotum and the processus vaginalis. Animal models are useful as they reveal some embryological processes that cannot be studies easily in humans, such as the potential role of the mammary line and the role of the genitofemoral nerve.