Mechanisms of Disease: normal and abnormal gonadal development and sex determination in mammals.
Sex differentiation in mammals occurs in three steps. The first is the establishment of chromosomal sex at fertilization, followed by the differentiation of the gonad into an ovary or testis, and finally the establishment of the phenotypic sex of the embryo and adult, which is regulated by the gonad. Disruption of any of these stages gives rise to sexual ambiguities that include 46,XY pure gonadal dysgenesis, 46,XX true hermaphroditism, and variable degrees of intersexuality. In this review, we focus on the development of the mammalian gonad from a bipotential primordium that differentiates into either an ovary or a testis. We describe the recent increase in our knowledge of the genetic defects that directly affect gonadal development, sex determination, and sex differentiation, with emphasis on the comparison of genetic studies in mice with studies of naturally occurring mutations in humans.
Val
Pierre
P
Institute of Cancer Research, London, UK.
Swain
Amanda
A
D000818:Animals; D005260:Female; D006066:Gonads / Q000002:abnormalities* / Q000254:growth & development*; D006801:Humans; D008297:Male; D051379:Mice; D019849:Sex Determination Processes