抄録
The estrogenic action of hexestrol and hexestrol propionate for inducing sex reversal was examined using a single brief treatment of early stage medaka （Oryzias latipes） embryos. Treatment of embryos with hexestrol or hexestrol propionate at high concentrations for 24 hrs resulted in complete sex reversal of genotypic males （XY） to functional females. The percentages of sex reversal varied from about 3.6% to 100% in the broad range of 1-1,000 ng/mL of hexestrol, dependent upon concentration. Hexestrol propionate at concentrations of 100 and 1000 ng/mL also induced the male-to-female sex reversal in about 9% to 83% of young fish. These results suggest that in the medaka, the brief exposure of early embryos to hexestrol or hexestrol propionate epigenetically affected sex differentiation in the late larval stage of growth.
