Poylmorphisms Of Porcine TAP1 Gene And Their Associations With Immune Indicator In Weaned Piglets

In this study, TAP I genes which is one of candidate genes about resisting porcine E.coli F18 was selected, its SNPs(single nucleotide polymorphisms) were detected, and their associations with immune parameters were calculated in four Anhui superior native pig breeds(Wei Pig, Wannan Black Pig, Anqing Liubai Pig, Huoshou Black Pig and Large White Pig).Primers were designed according to TAP1 (Number:BX323833) gene of Sus scrofa which was published in NCBI, polymerase chain reaction-single-strand conformation polymor-phism(PCR-SSCP) and sequencing were used to detected the genetic variation of 11 exons in coding sequences of TAP1. Analysis of GLM model in SPSS program were used to detected the associations between genetic variations and immune parameters in weaned piglets.In order to find the effective genetic markers of resisting E.coli F18 in native pig, and provide references of molecular biology for the study of germplasm characteristics and MAS in Anhui native pig breeds. The study showed that:(1) There were a T84C mutation in TAP1 in Huoshou Black Pig, a D443A mutation in TAP1 in all five pig populations of the experiment, a G6297C/G6298T mutation in TAP1 exon 8 in Wannan Black Pig, Wei Pig and Huoshou Black Pig, and a G7570A mutation in TAP1 exon 10 in all five populations of the experiment.(2) The results showed that a T�'C mutation at 84 bp, (the amino acids encoded by tryptophan to arginine),3 genotypes (AA, AB and BB)were found in Huoshou Black Pig. The genotypic frequency of AA, AB and BB were 67.32%,24.84% and 7.84% respectively. The polymorphism information content(PIC) was 0.2709 in Huoshou Black Pig, it was in average polymorphism situation. There was no mutation in the other three populations at 84bp locus, it was wild genotype. The results showed that a G�'A mutation at 443bp that did not cause the change of amino acid, and 3 genotypes(CC, CD and DD)were found in TAP1 gene in all five populations(Wei Pig, Wannan Black Pig, Anqing Liubai Pig, Huoshou Black Pig and Large White Pig) of the experiment. The genotypic frequency of CC were 9.21%,12.63%,17.24%, 62.09% and 10.92% respectively, the CD frequency were 31.58%,25.26%,31.03%, 29.41% and 29.31% respectively, the DD frequency were 59.21%,62.11,51.72%, 8.5% and 25.57% respectively. The polymorphism information content(PIC) were 0.3047,0.3063,0.3435,0.2929 and 0.3082 in the above five populations, they were all in average polymorphism situation. The results showed that a G�'C and G�'T linked mutation at 6297bp and 6298bp, the former caused the change of amino acids encoded from glutamic acid to histidine. The latter caused the change of amino acids from valine to leucine.2 genotypes (EE and EF) were found in TAP1 gene in Wei Pig, Wannan Black Pig and Huoshou Black Pig. The genotypic frequency of EE were 79.18%,66.67% and 92.16% respectively. The genotypic frequency of EF were 20.83%,33.33% and 7.8% respectively. The polymorphism information content(PIC) were 0.1706,0.2409 and 0.0725 in the above three populations, they were all in low polymorphism situation. But there was no mutation in exon 8 in Anqing Liubai Pig and Large White Pig populations, they were in wild genotype. The results showed that a G�'A mutation at 7570bp that did not cause the change of amino acid, and 3 genotypes(GG,GH and HH)were found in TAP1 gene in all five populations(Wei Pig, Wannan Black Pig, Anqing Liubai Pig, Huoshou Black Pig and Large White Pig). The genotypic frequency of GG were 17.97%,7.80%,7.97%,11.76%and 6.45% respectively. The genotypic frequency of GH were 40.76%,32.62%,12.50%,33.33% and 23.82% respectively. The genotypic frequency of HH were 41.27%,59.53%, 79.53%,54.90% and 69.73% respectively. The polymorphism information content(PIC) were 0.3611,0.2991,0.2142,0.3242and 0.2535 in the above five populations, they were all in average polymorphism situation.(3)χ2 test showed that the T84C highly significantly deviated from the Hardy-Weinberg equilibrium (P<0.01) in Huoshou Black Pig. The G443A highly significantly deviated from the Hardy-Weinberg equilibrium (P<0.01) in Wannan Black Pig and Large White Pig. The G7570A highly significantly deviated from the Hardy-Weinberg equilibrium (P<0.01) in Anqing Liubai Pig. Other loci all reached the Hardy-Weinberg equilibrium (P>0.05).(4) Comparison analysis of immune parameters were analyzed among the five populations, the content of IL-6 in Anqing Liubai Pig was significantly higher than that in Wei Pig (P<0.01). The content of IL-12 in Wei Pig was significantly lower than that in Anqing Liubai Pig and Large White Pig (P<0.05). The content of IFNy in Wei Pig was significantly higher than that in Anqing Liubai Pig and Large White Pig (P<0.01). The content of TNFa in Large White Pig was significantly lower than that in Anqing Liubai Pig and Wei Pig (P<0.01).(5) The association of G443A with immune parameters were analysed. The content of IL-6, IFNy and TNFa in Wei Pig, GG type was significantly higher than GA (P<0.05). The content of IL-10 in Large White Pig, AA type was significantly higher than GA (P<0.05).(6) The association of G7570A with immune parameters were analysed. The content of IL-10 in Anqing Liubai Pig, HH type was significantly higher than GA(P<0.05). The content of IFNy in Large White Pig, GA and AA type was significantly higher than GG (P<0.05).The study results suggested that the G443A、G7570A loci of TAP I gene should be helpful to be used as valid targeted points used in anhui local pig breeds, Anqing liubai pig, Wei pig, Houshou black pig and Large white pig disease resistance breeding.