Conservation of Y chromosome-specific sequences immediately 5' to the testis determining gene in primates.

Sex is determined in mammals by the SRY gene, which is located on the non-recombining region of the Y chromosome. Although the presence of mutations in SRY associated with male to female sex reversal clearly indicates that this gene is essential for testis formation, little is known concerning other genes in this process or how the expression of SRY itself is controlled. This is mainly due to the absence of an appropriate in vitro cellular model. Previous studies have indicated that SRY coding sequences are undergoing rapid evolution in mammals. In this study, we cloned and compared a Y chromosome-specific region immediately 5' to the SRY open reading frame in several primate species. The divergence of the region 5' to SRY between primates was found to be comparable with that described for autosomal sequences. An alignment of sequences within the primate lineage, together with sequences from the cow and pig, revealed the presence of several highly conserved motifs. These domains may have a function in the control of SRY expression during fetal development.