延黄牛ALDH1A1基因内含子4多态性及其与肉用性状的相关性分析

试验旨在研究乙醛脱氢酶1A1（acetaldehyde dehydrogenase 1A1，ALDH1A1）基因内含子4多态性及其对延黄牛肉用性状的影响。选取99头18月龄延黄牛母牛，采用PCR扩增产物Sanger直接测序法测定99头延黄牛ALDH1A1基因内含子4的单核苷酸多态性（SNP），运用SPSS 19.0软件分析ALDH1A1基因内含子4 SNP与延黄牛肉用性状（体高、体斜长、十字部高、胸围、腹围、管围、体重、背膘厚、眼肌面积和肌内脂肪）的关联性。结果显示，延黄牛ALDH1A1基因内含子4存在C/T突变位点，共发现3种基因型：TT、TC和CC，2种等位基因：T和C，其中TC为优势等位基因型，C为优势等位基因。卡方适合性检验结果发现，该SNP在延黄牛群体中处于Hardy-Weinberg平衡状态（P>0.05）。群体遗传参数分析发现，该突变位点的杂合度（He）相对较低，表明其在延黄牛群体中的变异较小，该位点属于中度多态（0.250.05）。结果表明，ALDH1A1基因内含子4在延黄牛中存在突变，能否作为延黄牛肉用性状的遗传标记有待于扩大样本数量进一步研究。

Polymorphism of ALDH1A1 Gene Intron 4 and Its Association with Meat Traits in Yanhuang cattle

This study was aimed to explore the effect of the polymorphism of acetaldehyde dehydrogenase 1A1 (ALDH1A1) gene intron 4 on meat traits in Yanhuang cattle.99 Yanhuang cattle at 18 months old were selected,the single nucleotide polymorphism (SNP) of ALDH1A1 gene intron 4 in Yanhuang cattle were detected by direct sequencing of PCR amplification products,and the correlation between ALDH1A1 gene intron 4 SNP and meat traits (body height,body length,cross height,chest circumference,abdominal circumference,tube circumference,body weight,back fat thickness,loin eye area and intramuscular fat) were analyzed using SPSS 19.0 software.The results showed that a C/T mutation had been found in ALDH1A1 gene intron 4,there were three genotypes (TT,TC and CC) and two alleles (T and C),TC was the dominant genotype,and C was the dominant allele.The chi-square test result showed that Yanhuang cattle population was in Hardy-Weinberg equilibrium (P>0.05).Population genetic parameter analysis showed the heterozygosity (He) of the mutation site was relatively low,there was a low varitation in Yanhuang cattle population,it was a moderately polymorphic (0.250.05).The results indicated that the polymorphism of ALDH1A1 gene intron 4 was found in Yanhuang cattle,it needed to expand the number of sample for further explore whether the site could be considered as genetic markers for meat traits in Yanhuang cattle or not.