Evolutionary Lineages of MHC Class II Genes and Association of Allelic Diversity With Mastitis in Indian Buffaloes

Abstract

The diversity of MHC class II genes directly influences the immune response against newlinepathogens in a species. It has more significance in those species, which are seemingly newlineexposed to a wider range of pathogens particularly in tropical regions of the world. Clinical newlinemastitis accounts for significant production losses and animal welfare concerns on dairy newlinefarms worldwide. In this study, MHC classII alleles were analysed for the water buffalo newline(Bubalus bubalis-Bubu), another economically important bovine species. Genetic diversity newlineanalysis of Bubu-ClassII loci helped in identification of 115 new alleles including 67 Bubu- DQA, 28 DQB, 6 DRA and 14 DRB3 alleles in 330 animals examined by PCR-RFLP newlinefollowed by cloning and sequencing of unique patterns. Phylogenetic analysis revealed the newlinedistribution of the buffalo DQA sequences in two major clusters of DQA1 and DQA2 genes, newlinesharing common lineages with corresponding cattle alleles, possibly due to trans-species newlineevolution. However, 6 highly divergent sequence, homologous to cattle (BoLA) DQA3 allele, newlinewas identified, indicating the existence of an additional new locus; DQA3 in buffalo. newline