野猪、民猪、大白猪μ-钙激活酶基因的变异位点分析

为了进一步研究CAPN1基因变异与肉嫩度的关系, 寻找与猪嫩度性状相关的分子标记, 对CAPN1基因组进行了克隆、测序, 并利用PCR-SSCP方法对其编码区序列进行了分子扫描, 寻找多态位点, 分析不同基因型在野猪、民猪、大白猪中的种间分布规律。获得了猪CAPN1基因的15个内含子序列; 根据GenBank上提供的CAPN1 CDS及克隆的内含子序列设计了5对多态性引物进行PCR-SSCP分析; 共找到8个SNPs, 其中7个位于外显子上, 1个位于内含子上, 并且外显子上的突变有3个是错义突变, 分别造成了蛋白质多肽链上第54位氨基酸的S/T、第192位氨基酸的G/E、第363位氨基酸的V/I替代; χ²独立性检验表明不同基因型在大白猪与野猪、民猪之间存在着极显著的差异(P<0.01), 野猪和民猪之间除了S1引物3种基因型的分布存在显著差异外(0.010.05)。这些多态位点具有成为分子标记的潜在可能。

The mutation site analysis on CAPN1 gene of Wild boar, Min pig and Yorkshire

In order to further evaluate the relationship between the variations of CAPN1 gene and meat tenderness, the CAPN1 genomic sequences were cloned and sequenced, its CDS was analyzed with PCR-SSCP, and the genotype analyses covered 109 individuals from Wild boar, Min pig and Yorkshire. Fifteen of total 21 introns were cloned. Five pairs polymorphic primers for PCR-SSCP analysis were designed based on the CDS of CAPN1 from GenBank and the cloned introns. Eight SNPs, resulting from single point mutation G to C, C to T, T to C, G to A, G to A, G to A, C to T and C to T at the base position 161 in exon2, 60 in exon5, 96 in exon5, 119 in exon5, 270 in intron8, 83 in exon10, 126 in exon13 and 138 in exon13 respectively, were identified, and 3 of which are missense mutations resulting to amino acid substitutions of S/T, G/E, V/I at the amino acid position of 54, 192 and 363 respectively. chi2 analysis showed that the distribution of genotypes among Yorkshire, Min pig and Wild boar are extremely significant difference, while there are no significant difference be-tween Min pig and Wild boar except in the S1 primer. The polymorphic sites may be used as molecular markers for meat tenderness and pork quality.