奶牛pIgR基因5′侧翼区SNP检测及其与IgA和IgM含量的相关性研究

SNP detection in 5′ flanking region of pIgR gene and association with IgA and IgM concentration in dairy cows

本试验研究了pIgR基因5′侧翼区的多态性及其对IgA和IgM含量的影响。从NCBI上的Map Viewer数据库下载牛pIgR基因的5′侧翼区的序列(NW_174143),长度为3.2 kb,设计4对引物进行PCR扩增,通过对25头奶牛的PCR产物直接测序发现并确定SNP位点,并用SNP Stream标签微列阵基因分型系统对189头牛进行基因分型,将其与牛奶和血液中的IgA和IgM的含量进行关联分析。结果表明,pIgR基因在-3128、-3072、-2834、-2348和-515位发现了5个SNP位点,其中SNP1和SNP2为A/G突变,SNP3、SNP4和SNP5为T/C突变。方差分析结果表明,SNP1对牛奶IgM和血液IgA含量有显着的影响(P<0.05),SNP3和SNP5对血液IgM含量有显着影响(P<0.05),其他SNP位点与单倍型组合对乳及血液中IgA和IgM的含量均没有显著影响(P<0.05);多重比较分析表明,SNP1位点的基因型AB个体与BB个体的牛奶IgM和血液IgA含量的最小二乘均数差异显著(P<0.05),SNP3和SNP5的不同基因型对血液IgM含量的最小二乘均数分别达到了显著水平(P<0.05)。因此得出,牛pIgR基因5′侧翼区的多态性影响牛奶和血液中的IgA和IgM的含量,这为进一步研究牛奶中IgA和IgM分泌转运机理提供了理论依据。

The objective of this study was to detect the polymorphism in the 5′ upstream region of bovine plgR gene and their associations with LgA and IgM concentrations in brood and milk. Based on the plgR gene 5′ flanking region sequence （NW_174143） downloaded from the Map Viewer database of NCB1, 25 genomic DNA samples of dairy cows were used for SNP detection. The 12-plex SNPstream genotyping was applied to 189 dairy cows and the association between the polymorphisms and the IgA and IgM concentrations in milk and blood were detected. We found five SNP Ioci; SNP1 and SNP2 were the A/G variation and SNP3, SNP4 and SNP5 were the T/C variation. Statistical analysis indicated that the SNP1 was significantly （P^0.05） associated with milk IgA and blood IgM concentrations, whereas SNP3 and SNP5 significantly affected blood IgM concentration （P〈0.05） ; other SNPs and diplotypes had no effect on the IgA and IgM concentrations, Cows with genotype AB of SNP1 were significantly （P〈0.05） different in milk IgM and blood IgA concentrations compared with those with genotype BB; cows with genotype AB had significantly （P〈0.05） higher milk IgM and blood IgA concentrations than cows with genotype BB. The different genotypes of SNP3 and SNP5 had considerable effects on blood IgM concentration （P〈0, 05）. These findings implied that the polymorphisms of 5′ flanking region in bovine plgR gene had an effect on IgA and IgM concentrations in milk and blood. Our results could provide references for further research on the mechanism of transportation of IgA and IgM into milk .