Evidence for Increased Cytoplasmic Androgen Binding in the Submandibular Gland of the Mouse with Testicular Feminization

Utilizing density gradient centrifugation, polyacrylamide gel electrophoresis, and equilibrium dialysis, the in vitro binding of [1,2-3H]dihydrotestosterone by cytoplasmic extracts of submandibular glands from normal mice was compared to that of mice carrying the X-linked gene for testicular feminization (Tfm). By these techniques it was shown that supernatant from Tfm animals (Tfm/Y) exhibit greater capacity and higher affinity for androgen binding than does supernatant from normal male mice. Since this high affinity binding was also demonstrable in preparations from heterozygous female (Tfm/X) but not from normal female mice (X/X), the abnormality appeared to be a valid and useful biochemical marker for the Tfm gene. Although the exact genetic mechanism that leads to this phenomenon is not clear, it is possible that the enhanced binding of androgen by submandibular gland cytoplasm may be involved in the pathogenesis of the male pseudohermaphroditism and the androgen resistance in the Tfm mouse.