Evolution, characterization and expression analysis of Sox gene family in rainbow trout (Oncorhynchus mykiss)

The Sox transcription factor family plays an important role in various biological processes such as animal sex determination and multiple organ development. We used online databases to analyze the gene structure, chemical characteristics, and evolutionary relationship of Sox family genes through bioinformatics, and we studied the expres-sion profiles and regulatory mechanisms of Sox family genes. A total of 29 rainbow trout Sox genes were identified. The phylogenetic analysis found that Sox genes of rainbow trout were clustered in seven subfamilies (B1, B2, C, D, E, F and H), and the gene structure of each subfamily was relatively conserved. Furthermore, Sox1, Sox4, Sox6, Sox8, Sox9, Sox11, Sox17, Sox18, and Sox19 developed into two copies, which might be the result of teleost fish-specific genome replication. Multiple HMG box domain alignments indicated that the motifs for all Sox sequences are conserved. Gene expression studies reveal that Sox expression is tissue-specific and that multiple Sox genes are involved in rainbow trout gonad and central nervous system development. Our study provides valuable informa-tion on the evolution of teleosts, and will also help to further research the functional characteristics of Sox genes.