We have sequenced the 5' region of the SRYgene from human, chimpanzee, sheep, and mouse and from four additional mammalian species, not previously characterized (gorilla, gazelle, rat, and guinea pig). In order to identify conserved DNA elements potentially involved in the regulation of the SRYgene, the newly determined sequences were analyzed and compared to all mammalian SRYpromoter sequences available at present. Ten highly conserved potential regulatory elements have been identified in all 10 species (AP1, Barbie, GATA, Gfi1, cMyb, vMyb, NF1, Oct1, Sp1, and SRY). The known function of several of these regulatory elements fits well with the known expression of the SRYgene. However, except for the highly conserved coding HMG motif, only a short region close to the initiation of transcription in the humanSRYis conserved in the exact position along the gene in all the species analyzed. This lack of sequence identity at the orthologous positions is consistent with the suggested rapid evolution of the SRYgene. This relative lack of homology contrasts with a high sequence identity of the putative regulatory sequences found within each taxonomic group of species (primates, bovids, and rodents), which supports a common mechanism of SRYexpression and possibly also a similar function.
