Allelic variant analysis of MHC DRB-1 coding region in Garole: The prolific sheep of India

Abstract

DRB-1 gene is encoded by class IIa region of the major histocompatability complex (MHC) and is one of the major expressed class II DRB genes in sheep. Certain DRB alleles have been associated with nematode infections, which is an economically important parasitic disease in sheep. In the present study, full coding region of the DRB-1 gene was characterized from random population of Garole sheep. Sequence analysis revealed that an open reading frame (ORF) was consisted of 801 base pair (bp) translating into a 266 amino acid long chain. High degree of nucleotide and amino acid polymorphism was found in the peptide binding region (PBR). Sequence comparison among DRB-1 transcripts of sheep breeds revealed that different alleles of DRB-1 of Garole corresponded to the DRB-1 allelic transcripts of sheep available in National Center for Biotechnology Information (NCBI). However, some alleles do not correspond and might be unique for Garole sheep. Results indicated that the majority of amino acid substitutions were located in the β-1 domain of the DRB-1 gene of Garole sheep.