In vitro effects of estradiol and aromatase inhibitor treatment on sex differentiation in Xenopus laevis gonads.

Gonads, still in the indifferent stage, were taken from tadpoles of Xenopus laevis and maintained in organ culture. These gonads were kept in good condition by frequent replacement of the culture medium and then underwent sexual differentiation. When the indifferent gonads were cultured in estradiol for 14 days, 90% of the explants showed female histological characteristics. The estradiol treatment of gonads in vitro gave results identical to those obtained from tadpoles treated in vivo. The gonads of X. laevis were successfully maintained for 14 days in vitro in a medium containing 20 microg/ml aromatase inhibitor (CGS 16949A). All the gonads treated with aromatase inhibitor showed the histological characteristics of the male phenotype. These results suggest that estradiol is important for ovarian differentiation in X. laevis. Copyright 2000 Academic Press.