Figure 2.

Protein-tyrosine phosphorylation and a sequence of events associated with spermatogenesis. For details of spermatogenesis and its associated signaling molecules (the full spelling of all abbreviations as well), see text. Note that MIS, Mullerian-inhibiting substance, is a testicular-differentiating factor that is produced in Sertoli cells and Leydig cells, whose differentiation is promoted by the actions of Sry and other sex-determining gene products. Also note that MIS acts in concert with testosterone. Note that positive regulators for protein-tyrosine phosphorylation are indicated in red circles