title: Analyzing the genetic characteristics and function of the swine leukocyte antigen 2 gene in a Chinese inbreed of pigs.
abstract: To study the genetic characteristics and function of swine leukocyte antigen (SLA) class I from the Hebao pig, a rare inbreed in China, a pair of primers was designed to amplify the SLA-2 gene (SLA-2-HB) and then the genetic characteristics of the gene were analyzed. The 3D homology modeling was used to analyze the structure and function of SLA-2-HB proteins. After cloning, sequencing and computer analysis, four SLA-2-HB alleles were found, all of 1119 bp. Sites 3-1097 were an open reading frame encoding 364 amino acids with two sets of intra-chain disulfide bonds comprising four cysteines situated in sites 125, 188, 227 and 283. By alignment of SLA-2-HB sequences with other SLA-2 alleles in the IPD database, 11 key variable amino acid sites were found in the extracellular domain of the SLA-2-HB alleles at sites 23(F), 24(I), 43(A), 44(K), 50(Q), 73(N), 95(I), 114(R), 155(G), 156(E) and 216(S), which could be used to differentiate other SLA-2 alleles. The 3D homology modeling demonstrated that the eight of 11 key variable amino acid sites were all in antigenic binding groove of SLA-2-HB proteins. The amino acid identities between SLA-2-HB and other SLA-2, SLA-1 and SLA-3 alleles were 86.2-97.0%, 85.0-93.9% and 83.3-88.6%, respectively. The phylogenetic tree of SLA-2-HB showed that it was relatively independent of the other SLA-2 genes. Furthermore, the SLA-2-HB alleles were similar to HLA-B15 and HLA-A2 functional domains and preserved some functional sites of HLA-A2. It was concluded that SLA-2-HB are novel alleles of SLA-2 and that the Hebao pig might have evolved independently in China.
authors.affiliation: Department of Biochemistry and Molecular Biology, College of Life Science and Technology, Dalian University, Dalian, China. gfsh0626@126.com
authors.forename: Feng-Shan
authors.initials: FS
authors.lastname: Gao
authors.forename: Jing
authors.initials: J
authors.lastname: Bai
authors.forename: Xiao-jie
authors.initials: XJ
authors.lastname: Gong
authors.forename: Xing-hui
authors.initials: XH
authors.lastname: Zhang
authors.forename: Wen-jun
authors.initials: WJ
authors.lastname: Zhang
authors.forename: Dan
authors.initials: D
authors.lastname: Guo
authors.forename: Sheng
authors.initials: S
authors.lastname: Zhang
mesh_terms: D000483:Alleles; D000818:Animals; D002681:China; D017931:DNA Primers / Q000235:genetics; D004220:Disulfides / Q000378:metabolism; D005260:Female; D014644:Genetic Variation; D015395:Histocompatibility Antigens Class I; D000949:Histocompatibility Antigens Class II / Q000737:chemistry / Q000235:genetics* / Q000276:immunology*; D007178:Inbreeding; D008297:Male; D008958:Models, Molecular; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D011487:Protein Conformation; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D013552:Swine
chemical_list: D017931:DNA Primers; D004220:Disulfides; D015395:Histocompatibility Antigens Class I; D000949:Histocompatibility Antigens Class II; C438668:swine leukocyte antigen