SRY and karyotypic status of one abnormal and two intersexual marsupials

Abstract

An intersexual agile wallaby (Macropus agilis) with apenis, a pouch and four teats had a sex-chromosome constitution of XXY inlymphocytes and cultured fibroblasts; the sex-determining region Y(SRY) gene was present, consistent with the presence ofa testis. An intersexual eastern grey kangaroo(Macropus giganteus) with a small empty scrotum and nopenis, and an abnormal red kangaroo (Macropus rufus)with no penis, pouch or teats, both had XX sex-chromosome complements; the SRYgene was not present, consistent with testis absence. The agile wallaby andgrey kangaroo described here provide further evidence that scrotal developmentin marsupials is independent of the Y chromosome. The cause of theabnormalities in the XX individuals cannot be determined until candidate genesare identified. These animals provide a basis for further genetic studies intomarsupial intersexuality and sex differentiation.