Polymorphism Analysis Of SLA-DQB And DRB Gene With PCR-RFLP And A New Allele Of SLA-DQB Isolated From Wuzhishan Pigs

College of Animal Science and Technology, Nanjing Agricultural University, 210095, P. R. ChinaThe restriction polymorphism of the exon 2 of SLA-DQB and DRB gene in Wuzhishan, Erhualian and Pietrain Pigs was investigated by PCR-RFLP. Nine kinds of SLA-DQB PCR-restriction fragment length polymorphism (RFLP) pattern types were observed for both HaeIII (7 RFLP pattern types) and RsaI(6 RFLP pattern types). There were 3, 3 and 5 kinds of PCR-RFLP pattern types in Wuzhishan, Erhualian and Pietrain Pigs, respectively. A total of five kinds of SLA-DRB PCR-RFLP pattern types were defined using MspI (1 RFLP pattern types) and Rsal (5 RFLP pattern types). There were 2, 3 and 3 kinds of PCR-RFLP pattern types in Wuzhishan, Erhualian and Pietrain Pigs, respectively.The PCR product of PCR-RFLP pattern type of A in Wuzhishan was cloned into vector and sequenced using standard protocols, and an automated sequencer. As a result, a new SLA-DQB allele was found in Wuzhishan, a Chinese native pig. The DNA sequence has been submitted to the Genbank DNA Sequence Database under accession number AY281361. This new allele sequence has a new mutation in the peptide-binding groove.The PCR-RFLP pattern type of BCFGHHIJ in both SLA-DQB and DRB gene was named a pattern type, and the PCR-RFLP pattern type of CCFFHHII in both SLA-DQB and DRB was named b pattern type. Three immunological indexes, such as the transformation ratio of lymphocyte, the content of IgG in serum and the PHA test of skin, were measured in the pigs of the two PCR-RFLP pattern types. As a result, the abilitiy of pigs of heterozygote (a pattern type) was stronger than it of homozygote (b pattern type) on disease resistance.