ANT3 AND STS ARE AUTOSOMAL IN PROSIMIAN LEMURS - IMPLICATIONS FOR THEEVOLUTION OF THE PSEUDOAUTOSOMAL REGION

Comparative in situ hybridization in various primate species has revea led a pseudoautosomal location for the human ANT3 gene and an X-specif ic location for the steroid sulfatase (STS) gene throughout the higher primate species up to the New World monkeys. However, ANT3 and STS ma p together on an autosome of two prosimian species of the genus Lemur and Eulemur. These results suggest an autosome-to-X/Y translocation af ter the simians radiated from the prosimians, resulting in a pseudoaut osomal location of genes such as ANT3 and STS. In simian primates, STS then became X-specific by a pericentric inversion in the Y chromosome followed by mutational inactivation of the Y allele.