Molecular characterization of MHC class II DRA cDNA in Deoni cattle

Abstract

The present study was undertaken to clone and characterize DRA gene in Deoni cattle. The cDNA for the DRA gene was amplified by using specific primers designed based on available cattle sequences and purified products were cloned in competent E.coli (DH5á) strain. The full length 1013bp product of cDNA of DRA contained a single ORF of 762 nucleotides that coded for 253 amino acids translated product. Twenty four amino acids formed signal peptide while 229 constituted mature peptide. The deduced amino acid sequences resembled those of class II molecules of other species for all the conserved residues having critical functional role. But a single N-linked glycosylation site in á1 was observed in cattle and buffalo when compared to human and swine which contain a second site in á2 domain. The signal peptide was found more variable among the species compared. Comparison of nucleotide and amino acid sequences among related species and dendrogram constructed revealed that the cattle sequences are more similar to buffalo sequences.