Beta-defensin genes of the Colubridae snakes Phalotris mertensi , Thamnodynastes hypoconia , and T. strigatus

β-Defensins are cationic antimicrobial peptides showing little sequence similarity but highly conserved tertiary structure stabilized by a six-cysteines-motif. Using a PCR approach, we described β-defensin sequences with two exons in three species of Colubridae snakes with high sequence similarity between them. The deduced amino acid sequence presented the characteristics of β-defensin family. The phylogenetic analysis using β-defensin coding sequences of different snakes grouped them in two main branches: genes organized in three or two exons.