title: Nucleotide sequence and polymorphism of MHC class II DQB exon 2 alleles in Chinese yakow (Bos grunniens × Bos taurus).
abstract: The objective of this study is to describe the gene characteristics of the bovine lymphocyte antigen (BoLA)-DQB exon 2 locus in Chinese yakow (Bos grunniens × Bos taurus) and to compare it with previously reported patterns in other bovidae species to investigate genetic factors for disease resistance. The exon 2 of the MHC class II DQB gene was cloned and sequenced. It was revealed by sequence analyses that there are 36 DQB exon 2 alleles among 44 Chinese yakow. These alleles exhibited a high degree of nucleotide and amino acid polymorphism with most amino acid variations occurring at positions forming the peptide-binding sites (PBS). The DQB loci were analysed for patterns of synonymous (dS ) and nonsynonymous (dN ) substitution. The Chinese yakow was observed to be under strong positive selection in the DQB exon 2 peptide-binding sites (dN = 0.147, P < 0.01). It appears that this variability among Chinese yakow confers the ability to mount immune responses to a wide variety of peptides or pathogens.
authors.affiliation: Faculty of Animal Science and Technology, Yunnan Agricultural University, Kunming, China.
authors.forename: D
authors.initials: D
authors.lastname: Xi
authors.forename: T
authors.initials: T
authors.lastname: Hao
authors.forename: Y
authors.initials: Y
authors.lastname: He
authors.forename: J
authors.initials: J
authors.lastname: Leng
authors.forename: Y
authors.initials: Y
authors.lastname: Sun
authors.forename: Y
authors.initials: Y
authors.lastname: Yang
authors.forename: H
authors.initials: H
authors.lastname: Mao
authors.forename: W
authors.initials: W
authors.lastname: Deng
mesh_terms: D000483:Alleles; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D002417:Cattle; D002681:China; D003001:Cloning, Molecular; D003433:Crosses, Genetic; D005091:Exons; D005260:Female; D056426:Genetic Loci; D000949:Histocompatibility Antigens Class II / Q000145:classification / Q000235:genetics* / Q000276:immunology; D007113:Immunity, Innate; D008297:Male; D008969:Molecular Sequence Data; D010802:Phylogeny; D011110:Polymorphism, Genetic; D011485:Protein Binding; D016415:Sequence Alignment
chemical_list: D000949:Histocompatibility Antigens Class II