Sequence Analysis and Polymorphism Discovery in 4 Members of the Bovine Cathelicidin Gene Family

Cathelicidins (CATHLs) are small, cationic antimicrobial peptides that establish an early innate immune defense against infections in mammals. Beyond their wide spectrum of antimicrobial activity, these peptides play important roles in wound repair, chemotactic activity, and apoptosis. Thus, polymorphisms present in bovine CATHLs 2, 5, 6, and 7 could potentially underlie inherited differences in innate immunity and disease resistance. The purpose of the present study was to characterize single nucleotide polymorphisms (SNPs) and insertion-deletion (indel) polymorphisms within the bovine CATHL gene family. Comparative sequence analysis for 10 domestic cattle breeds representing both Bos taurus and Bos indicus revealed 60 SNPs, 7 of which were nonsynonymous and 5 indel mutations. Characterization of these novel polymorphisms is central to developing a firm understanding regarding what effects, if any, nonsynonymous CATHL variation has with respect to bovine innate immunity.