GENETIC-CONTROL OF GONADAL DIFFERENTIATION

The study of naturally occurring mutations in humans and induced mutat ions in mice that cause sex reversal has been instrumental in the clon ing and functional analysis of genes involved in gonadal differentiati on. Several genes required for this complex developmental process have now been identified. The genes LIM1, WT1 and FTZ-F1 have been demonst rated to be involved in the formation of the gonads prior to their dif ferentiation as testes or ovaries. Subsequent sex-specific gonadal dif ferentiation appears to be mediated by the SRY and SOX9 genes in the t estis, and the DAX-1 gene in the ovary.