牛α辅肌动蛋白(α-Actinin)1 基因遗传变异与产犊数性状的相关性

为了探讨辅肌动蛋白1(α-actinin1)基因对母牛产犊数的影响,以鲁西单胎牛，鲁西双胎牛，南阳牛，晋南牛，荷斯坦牛，三河牛和延边牛为研究对象，以α-actinin1为影响产犊数的候选基因，分别扩增418 bp和505 bp 2个片段，采用直接测序，RFLP-RsaⅠ和RFLP-Apa Ⅰ方法检测α-actinin1基因的多态性，并将其与产犊数性状进行了关联分析.在内含子15 第227 nt处的碱基发生G→A突变，和内含子10第3 124 nt处发生A→G突变，使其产生酶切多态.对2个酶切多态位点进行基因型分型，χ2检验表明：在G227A位点，除了鲁西单胎牛外，其他群体都已达到Hardy-Weinberg平衡；在A3 124G位点，除了鲁西双胎牛外，其余群体都已经达到Hardy-Weinberg平衡.SAS 9.0的最小二乘拟和一般线性模型分析结果表明：A3 124G位点的AG基因型的产犊数的最小二乘均数极显著（P＜0.01）高于基因型AA；而单倍型组合G G的产犊数的最小二乘均数显著高（P＜0.01）于其它3种单倍型组合.α-actinin1基因有可能作为产犊数性状的候选分子的遗传标记.

Genetic Variation of a-Actinin 1 Correlates with Cattle Twinning Trait

The aim is to investigate whether the α-actinin1 gene polymorphism correlates with the calving number in cattles. Two SNP sites within the α-actinin1 gene were identified based on the　sequence analysis in the Luxi cattle; the Luxi twinning cattle, the Nanyang cattle, the Jinnan cattle, the Holstein cattle, the Sanhe cattle and the Yanbian cattle. The SNP1 was G/A (227) in intron 15 and SNP2 was A/G (3 124) in intron 10 of the α-actinin1 gene. Their correspondent RFLP-RsaⅠ and RFLP-ApaⅠ were analyzed to evaluate the genetic polymorphisms in association with the number of calving. We found that all the breeds except the Luxi cattle reached Hardy Weinberg equilibrium in SNP1 locus by chi-square analyses. In SNP2, the breeds reached Hardy Weinberg equilibrium except for the Twinning Luxi cattle. The result of least square means showed that the cattle with diplotype genotype SNP2 G-G had the highest number of calving (P-＜0.01), and the SNP2 A-G diplotype had significant higher number of calving (P＜0.01) than that of SNP2 A-A.Our findings implied that the polymorphism analysis of α-actinin1 gene could be an useful approach in the cattle selection of calving number trait.