SRY-related genes in the genome of the rice field eel (Monopterus albus).

The mammalian sex determining gene, SRY, is the founding member of the new growing family of Sox (SRY-like HMG-box gene) genes. Sox genes encode transcription factors with diverse roles in development, and a few of them are involved in sex determination and differentiation. We report here the existence of Sox genes in the rice field eel, Monopterus albus, and DNA sequence information of the HMG box region of five Sox genes. The Sox1, Sox4 and Sox14 genes do not have introns in the HMG box region. The Sox9 gene and Sox17 gene, which each have an intron in the conserved region, show strong identity at the amino acid level with the corresponding genes of mammals and chickens. Similar structure and identity of the Sox9 and Sox17 genes among mammals, chickens and fish suggest that these genes have evolutionarily conserved roles, potentially including sex determination and differentiation.