Sequence variability in the BLB2 region among guinea fowl and other poultry species

Abstract

The BLB2 gene is a predominantly expressed MHC class II gene in chicken and has not been characterized in guinea fowl. In view of the resistance of guinea fowl to most of the chicken diseases, nucleotide sequence variability in b1 and b2 domains of BLB2 gene was studied between guinea fowl and other poultry species such as chicken, quail, pheasant and duck. The b1 and b2 domain of BLB2 gene in guinea fowl was 270 and 282 nucleotides in size and showed no size variation with other poultry species. Between-species percent nucleotide variability ranged from 24.07 to 30.00% in b1 domain, while inb2 domain percent nucleotide variability was 8.16 - 10.99%. Between the species, guinea fowl showed low and similar genetic distances (0.149 - 0.159) with all other poultry species, except with duck (0.287). The phylogenetic tree, based on nucleotide variability in b1 and b2 domains from these poultry species clearly revealed that duck MHC are clustered separately. Among other poultry species (chicken, quail, pheasant and guinea fowl), the guinea fowl, branched out separately within the cluster comprising of galliformis species. Key words: BLB2, guinea fowl, nucleotide variability, genetic distance