中文摘要：

采用测序的方法鉴定136头中国荷斯坦奶牛ELOVL5基因启动子区域的遗传多态性位点，通过统计学分析遗传多态性位点与乳质性状的关联性，并根据差异显著性多态性位点构建ELOVL5基因启动子双荧光素酶报告载体，检测不同基因型的启动子活性。结果表明：在奶牛ELOVL5基因启动子区域中发现了7个SNPs及1个单碱基缺失突变，其中SNP7g．-385C〉G与尿素氮、校正奶量显著相关（P〈0．05），单碱基缺失突变与牛奶中的体细胞数极显著相关（P〈0．01）。双荧光素酶报告载体检测结果显示，缺失纯合基因型的启动子活性极显著高于野生型（P〈0．01）。

英文摘要：

The objective of this study was to evaluate the association between ELOVL5 gene poly- morphisms and milk quality of Holstein cattle. Using direct DNA sequencing,seven single nucleo- tide polyraorphisrns（SNPs）and 1-bp del polymorphism were identified within the promoter region of ELOVL5 gene from 136 individuals. According to the statistical analysis,l-bp ins/del polymor- phism was significantly associated with somatic cell count（SCC）（P〈0.01） ,and SNPTg. -385C〉 G was significantly associated with urea nitrogen and corrected milk yield（P〈0.05）. Then the transcriptional activities of different genotypes were determined using a dual-luciferase reporter assay system in bovine mammary epithelial cells（MECs）,the homozygous 1-bp del mutation geno-type increased by a 1.59-fold（P〈0.01） activity of luciferase compared with the wild type.