摘要跨膜蛋白18基因(Transmembrane protein 18, TMEM18)在神经系统表达。全基因组关联分析(GWAS)表明，该基因的突变会影响人类肥胖和Body Mass Index(BMI)值变化。本研究采用DNA池测序技术检测了郏县红牛(Bos taurus) TMEM18基因5个外显子和部分内含子区单核苷酸多态(single nucleotide polymorphism, SNP)位点，通过PCR-RFLP技术对所发现的SNP位点进行分型验证，然后分析不同基因型与郏县红牛生长性状的关联性。结果表明，在郏县红牛TMEM18基因上共发现了3处新的SNPs：NW_003099175.1: g. 2303G>A、 g. 3835 G>A 和 g. 3865 A>G(aa. Gly>Ser)。关联分析结果表明，郏县红牛TMEM18基因g. 2303G>A位点AA型个体体高、体长、胸围和体重显著大于GG型(P<0.05)，郏县红牛TMEM18基因g. 3835 G>A位点AG型个体胸围和体重显著大于AA型(P<0.05)。研究结果提示，这两个位点可作为郏县红牛品种体尺和体重生长性状选择的分子育种候选标记。
Abstract：Transmembrane protein 18 gene(TMEM18) is expressed in the central nervous system that has recently been linked to human obesity and body mass index (BMI) in genome wide association studies (GWAS). In this study, direct DNA pool sequencing and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) methods were used to genotype novel SNPs in TMEM18 gene, and then analyzed associations between different genotypes and growth traits in Jiaxian Red cattle(Bos taurus). Three novel SNPs were detected in Jiaxian Red cattle TMEM18 gene: NW_003099175.1: g. 2303G>A, g. 3835 G>A and g. 3865 A>G(aa. Gly>Ser). Significant association analysis revealed that the individuals with genotype AA had a larger body height, body length, heart girth and body weight than that of the individuals with genotypes GG at g.2303 A>G locus(P<0.05), The result also suggested that the individuals with genotype AG had a larger body weight and heart girth than that of the individuals with genotype AA at g. 3835 G>A locus (P<0.05). Therefore, these two loci can be used as body size and body weight candidate markers to breed Jiaxian Red cattles.
