Studies On The Population Molecular Genetic Structure Of Exon 2 About SLA-DQB, DRB Genes In Six Miniature Pig Breeds

Major histocompatibility complex (MHC) antigen was such gene cluster that linked with certain chromosome encoding a group of cell membrance glycoprotein that correlated with immune response. Its function was not only confined in rejection of transplantation but also correlated with immune response for extra-antigen. Major histocompatibility complex was the most polymorphism in gene system. Here 198 pigs for SLA-DQB and 98 pigs for SLA-DRB were detected, the exon 2, partial intron 1, and partial intron 2 of genes were studied by PCR-RFLPs and clone sequencing in Ganzhi Zang pigs(Tibet pigs), Hezuo pigs, Diannan Small-eared pigs, Hebao pigs, Wuzhishan pigs and Bama miniature pigs.After the exon 2 of SLA-DQB gene was digested by RsaI, the results were showed that 5 alleles and 14 genotypes(five to ten in each groups); values of the He were between 0.5384～0.7288, among them, the value of He in Huabei group was highter than that in Huanan group, and that value in Huanan group was highter than that in Gaoyuan group; the variation of PIC was 0.4884 to 0.7285. The results ofχ~2 showed that five alleles of RsaI locus in Ganzhi Zang pigs, Bama pigs and Wuzhishan pigs were fit with Hardy-Weinberg equilibrium, but not in Hezuo pigs, Diannan pigs and Hebao pigs.After the exon 2 of SLA-DQB gene was digested by HinfI, the results were showed that we received 3 alleles and 6 genotypes, the distribution in different groups was Huabei group is the most and Huanan group is the least, PIC was among 0.2908 to 0.4610, and the distribution Trend was the same with He, the locus was moderately polymorphic. The results ofχ~2 showed that 3 alleles of Hinfl locus in Ganzhi Zang pigs,Diannan pigs,Bama pigs and Hebao pigs were fit with Hardy-Weinberg equilibrium, Hezuo pigs and Wuzhishan pigs were not.After the exon 2 of SLA-DRB gene was digested by RsaI in three breeds and 98 pigs, the results were showed we received 5 alleles(R,S,T,U,V) and 9 genotypes. In the three groups, the allele frequency of S was the most(0.6786), and the allele frequency of V was the least(0.0562), the distribution from high to low of PIC and He was Hezuo pigs, Wuzhishan pigs and Hebao pigs. The results ofχ~2 showed that 3 alleles of RsaI locus in Hezuo pigs were not significant difference, fit with Hardy-Weinberg equilibrium, Wuzhishan pigs and Hebao were not fit with Hardy-Weinberg equilibrium.After the exon 2 of SLA-DRB gene was digested by MspI in three breeds, the results were showed we received 2 alleles and 3 genotypes(PP,QQ,PQ), the allele frequency of Q(0.5918) was more than P(0.4082), the distribution from high to low of PIC and He was Hebao pigs, Hezuo pigs, and Wuzhishan pigs. The results ofχ~2 showed that 3 alleles of MspI locus in Hezuo pigs and Wuzhishan pigs were not significant difference (P＞0.05), fit with Hardy-Weinberg equilibrium pigs, Hebao was not.Fifteen alleles were seperated and nomenclatured based on the 26 cloning sequnces in the experiment. the SLA-DQB exon 2 haplotype (gene) diversity was 0.9140, nucleotide average difference was 12.215. Elenve alleles were seperated and nomenclatured based on the 11 cloning sequnces in the experiment, the SLA-DRB exon 2 haplotype (gene) diversity was 0.909, nucleotide average difference was 22.875, the SLA-DRB gene had more rich nucleotide difference and amino acids difference than SLA-DQB.