Association between polymorphisms of the swine MHC-DQA gene and diarrhoea in three Chinese native piglets.
Swine leucocyte antigen (SLA) is a highly polymorphic multigene family that plays a crucial role in swine immune response and disease resistance. Here, we identified polymorphisms and gene variations of SLA-DQA exon 2 using polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) and DNA sequencing analysis, and further investigated the correlation between the polymorphisms and piglet diarrhoea in three Chinese native pig breeds (Bamei, Juema and Gansu Black pigs). Consequently, 12 genotypes and 8 alleles including two novel alleles were detected. Nucleotide polymorphism was compared with the actual functional polymorphism in the peptide-binding region (PBR), binding pockets P1, P6 and P9, and the antigen-binding groove, variations in the antigen-binding groove of alleles DQA*01xa01, DQA*01xa03, DQA*01xb01, DQA*We02, DQA*03xb03 and DQA*wy06 were higher than alleles DQA*03xa01 and DQA*03xa03, while amino acid variations in peptide-binding pockets of allele DQA*03xa03 were most abundant among all alleles. The results of association analysis showed the diarrhoea score of Gansu Black pigs (-0.08 ± 0.78) was significantly higher than Bamei and Juema pigs (P < 0.01), and genotype DQA*03xa0103xa01 (0.39 ± 0.54) was significantly higher relative to other genotypes (P < 0.01), while that of genotype DQA*03xa0303xa03 (-1.31 ± 0.88) was markedly lower than scores obtained with genotypes DQA*03xa0103xa01 and DQA*03xa0101xa01 (P < 0.01), as well as DQA*01xa0101xa01 (P < 0.05), indicating that amino acid variations in the peptide-binding pockets play a more important role than the antigen-binding groove in piglet diarrhoea resistance. Further studies on other SLA molecules of native pigs are required to validate the link between this gene complex and diarrhoea.
College of Animal Science and Technology, Gansu Agricultural University, Lanzhou, China.|College of Life Science and Engineering, Northwest University for Nationalities, Lanzhou, China.
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Liu
College of Animal Science and Technology, Gansu Agricultural University, Lanzhou, China.
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Zhao
College of Animal Science and Technology, Gansu Agricultural University, Lanzhou, China.|College of Life Science and Engineering, Northwest University for Nationalities, Lanzhou, China.
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Lu
College of Animal Science and Technology, Gansu Agricultural University, Lanzhou, China.
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Yang
College of Animal Science and Technology, Gansu Agricultural University, Lanzhou, China.
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Huang
College of Animal Science and Technology, Gansu Agricultural University, Lanzhou, China.|Gansu Research Center for Swine Production Engineering and Technology, Lanzhou, China.
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Gun
D000483:Alleles; D000818:Animals; D003967:Diarrhea / Q000662:veterinary*; D005091:Exons; D005787:Gene Frequency; D005802:Genes, MHC Class II; D056726:Genetic Association Studies; D020022:Genetic Predisposition to Disease; D005828:Genetics, Population; D005838:Genotype; D015395:Histocompatibility Antigens Class I; D000949:Histocompatibility Antigens Class II / Q000235:genetics; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D018807:Polymorphism, Single-Stranded Conformational; D013552:Swine / Q000235:genetics*; D013553:Swine Diseases
D015395:Histocompatibility Antigens Class I; D000949:Histocompatibility Antigens Class II; C438668:swine leukocyte antigen