Preliminary Report on Sex Differentiation in Germ Cells of Normal and Transplanted Gonads in the Fish, Oryzias latipes

Abstract

In the medaka, Oryzias latipes, much data on the mechanism involved in sex differentiation have been accumulated by Yamamoto and his co-investigators. On the basis of the following facts obtained from the oral administration of exogenous steroids, 1. the specific activity of sex steroids as exogenous sex inducers, 2. the very low effective dosage of these sex steroids as the inducers, 3. the selective incorporation of sex steroids into the differentiating gonads, they reached the conclusion that the sex steroids are natural sex inducers (cf. Yamamoto, 1969). In this report some results of our recent experiments are summarized.