Breeding of Sex-reversed Males of Xenopus laevis Daudin.

Abstract
Summary Xenopus larvae of male genetic sex develop into phenotypic females, if raised in weak solutions of estradiol (25 to 1000 μg/1). Such feminized males, if bred to normal males, produce uniformly male offspring. It is concluded that in Xenopus the males are the homozygous sex and that phenotypic sex reversal does not affect the male genetic constitution. The practicability of breeding entirely homozygous male and female laboratory stock of Xenopus is pointed out.