Genome-Wide Association Study Reveals the PLAG1 Gene for Knuckle, Biceps and Shank Weight in Simmental Beef Cattle

Carcass traits of beef cattle have been genetically improved to increase yield of high quality meat. Genome-wide association study (GWAS) is a powerful method to identify genetic variants associated with carcass traits. For the 770K genotyped SNPs from 1141 Chinese Simmental cattle, we used the compressed mixed linear model (CMLM) to perform a genome-wide association study for knuckle, biceps and shank of beef carcass traits. Seventeen significantly associated SNPs were found, which are located on BTA6, BTA14 and BTA15. Interestingly, one pleiotropic quantitative trait nucleotide (QTN), named BovineHD1400007259 (p −8) within the well-known gene region PLAG1-CHCHD7 on BTA14, was found to govern variation of the knuckle, biceps and shank traits. The QTN accounted for 8.6% of phenotypic variance for biceps. In addition, 16 more SNPs distributed on BTA14 were detected as being associated with the carcass traits.

肉牛胴体性状已通过遗传改良以提升优质肉的产量。全基因组关联分析（Genome-wide association study, GWAS）是鉴定与胴体性状相关遗传变异的有效方法。本研究针对1141头中国西门塔尔牛的770K基因分型单核苷酸多态性（Single Nucleotide Polymorphism, SNP），采用压缩混合线性模型（compressed mixed linear model, CMLM）对肉牛胴体的腱子、臂肌和小腿肉性状开展全基因组关联分析。研究共鉴定到17个显著关联的SNP，分别定位于牛6号、14号和15号常染色体（BTA6、BTA14、BTA15）。值得注意的是，位于牛14号染色体PLAG1-CHCHD7经典基因区域内的一个名为BovineHD1400007259（p−8）的多效性数量性状核苷酸（quantitative trait nucleotide, QTN），可调控腱子、臂肌和小腿肉性状的表型变异。该QTN可解释臂肌性状8.6%的表型方差。此外，本研究还在牛14号染色体上检测到另外16个与该胴体性状相关的SNP。