Bioinformatic and molecular characterization of beta.defensin like peptides isolated from the green lizard Anolis carolinensis

The high resistance of lizards to infections indicates that anti-microbial peptides may be involved. 25 Through the analysis of the green lizard (Anolis carolinensis) genome and the expressed sequence tag 26 (EST) libraries 32 beta-defensin-like-peptides have been identified. The level of expression of some of 27 these genes in different tissues has been determined by semi-quantitative RT-PCR. Gene expression 28 and structure analysis suggest the presence of alternative splicing mechanisms, with a number of exons 29 ranging from two to four, similar to that for beta-defensins genes in mammals. Lizard beta-defensin-like 30 peptides present the characteristic cysteine-motif identified in mammalian and avian beta-defensins. 31 Phylogenetic analysis indicates that some lizard beta-defensins-like peptides are related to crotamine 32 and crotamin-like peptides of snakes and lizards suggesting that beta-defensins and venomous peptides 33 have a common ancestor gene.