Induction of Müllerian duct derivatives in testicular feminized (Tfm) mice by prenatal exposure to diethylstilbestrol.

When pregnant mice carrying the Tfm mutation gene were injected with diethylstilbestrol (DES) from Days 9 to 16 of gestation, the regression of the Müllerian duct derivatives was inhibited in their wild male and Tfm male offspring. The degree of persistence of the Müllerian duct derivatives demonstrated a dependence on DES dose. Complete or almost complete preservation of the Müllerian ducts was observed in the animals exposed to high doses of DES. Since Tfm males from non-injected mothers had no reproductive tract except the vaginal anlage, despite the presence of testes, bilateral occurrence of the Müllerian duct derivatives in Tfm males following prenatal exposure to DES indicates that the characteristic features of the reproductive tract in these animals are almost the same as that in normal females.