Bioinformatic and molecular characterization of cathelicidin-like peptides isolated from the green lizard Anolis carolinensis (Reptilia: Lepidosauria: Iguanidae).

摘要

The high resistance to infections in lizards indicates that these reptiles possess active processes of innate immunity including the production of antimicrobial peptides. The present bioinformatic and molecular study on the lizard Anolis carolinensis reports the presence of three cathelicidin-like-genes and their deduced peptides. These antimicrobial peptides have been named as AcCATH-1, -2 and -3, and represent the first cathelicidins so far identified in lizards. These peptides contain the characteristic cathelin-like domain identified in cathelicidins present in other species of vertebrates. The expression of the three genes in different tissues of healthy lizards has been determined by semi-quantitative reverse transcription polymerase chain reaction (RT-PCR). Lizard cathelicidin genes show a genome organization similar to that of mammals but with a number of exons ranging from three to five. The gene coding for AcCATH-3 is missing the third exon, like two cathelicidins found in fish. Gene expression analysis suggests the presence of alternative splicing mechanisms. Cathelicidins and beta-defensins recently found in this lizard suggest that these peptides elicit effective protection against infections in these reptiles.