Sequences homologous to ZFY, a candidate human sex-determining gene, are autosomal in marsupials

Abstract

Sexual differentiation in placental mammals results from the action of a testis-determining gene encoded by the Y chromosome. This gene causes the indifferent gonad to develop as a testis, thereby initiating a hormonal cascade which produces a male phenotype1,2. Recently, a candidate for the testis-determining gene (ZFY, Y-borne zinc-finger protein) has been cloned3,4. The ZFY probe detects a male-specific (Y-linked) sequence in DNA from a range of eutherian mammals, as well as an X-linked sequence (ZFX) which maps to the human X chromosome3. In marsupials it is also the Y chromosome that seems to determine the fate of the gonad, but not all sexual dimorphisms5. Using the ZFY probe we find, ..