Hormonal Control of Sex Differentiation

Abstract

This article is a review of the role of hormones in sex differentiation and exptl. sex reversal, considered chiefly from the view-point of the embryonic structures involved. The rudimentary parts of the sex complex are discussed in terms of their embryonic constitution and future representation in the definitive sex equipment; while the hormones involved in differentiation are taken up with reference to their mode of action[long dash]whether direct or indirect, stimulatory or inhibitory. In the differentiation of the gonad it appears that the characteristic effect of the hormone is an inhibitory action on the heterotypic gonad component; while the gonoducts probably respond to direct stimulation by the appropriate hormone, although in some circumstances an inhibitory effect on the heterotypic duct is indicated. The external genitalia of mammals behave rather as male characters in spite of their representation in both sexes. The data available strongly suggest that these parts are unresponsive to female sex hormones. Other topics, such as the quantitative aspects of hormone action, and the relations of embryonic sex-differentiating substances and adult hormones, are briefly presented.