Embryonic sex hormones in birds

Abstract

Hormone activity of embryonic gonads in birds was demonstrated by grafting and culture experiments. Anti-Mullerian hormone responsible for the regression of the Mullerian ducts in the male is most probably a glycoprotein. Whether the testis also secretes testosterone has long been disputed, but most arguments are against this possibility. From early stages of development, the ovary secretes estrone and estradiol. However, it could not be demonstrated unambiguously whether estrogen is identical with the sex inducing substance in the female. The hypophysis seems to control ovarian estrogen secretion at 10-13 days of incubation in the chick embryo.