湘西黄牛LPL基因第2外显子的遗传多态性及其与生长性状的关联分析

摘要

In order to study the genetic characters of Xiangxi cattle and search the molecular markers related to growth traits, single nucleotide polymorphisms ( SNPs) of exon 2 in LPL gene were detected by CRS-PCR-RFLP and sequencing, and correlation between genotype of LPL gene and growth traits were analyzed. The results indicated that tiro SNPs of g. 355420C＞T and g. 355427T＞A were detected in exon 2 of LPL gene of Xiangxi cattle, and two mutations mentioned above were in moderate polymorphisms in Xiangxi cattle population. The SNP of g. 355420C＞T was a novel mutation , and g. 355427T＞A caused an amino acid substitution ( Thr changed into Ser). The results of association between genotype and growth traits showed that body height, body weight and body length of individuals with CC genotype were significantly more than those with genotypes TT and CT (P＜ 0. 05) , and C allele positively affected the growth traits of Xiangxi cattle. The body height, body length, heart girth and body weight of individuals with genotypes TT and AT were significantly more than those with genotype AA (P＜ 0. 01) , and T allele positively affected the growth traits of Xiangxi cattle. The results suggested that g. 355420C＞ T and g. 355427T＞A of exon 2 in LPL gene of Xiangxi cattle affected the growth traits of Xiangxi cattle, and could be potential molecular markers for breeding.%为了探讨湘西黄牛分子遗传特征及寻找与生长性状相关的分子标记,采用创造酶切位点PCR-RFLP(CRS-PCR-RFLP)和测序技术检测了湘西黄牛LPL基因第2外显子的多态性,并进行了LPL基因的基因型与湘西黄牛生长性状的关联分析.多态性分析结果表明,湘西黄牛群体LPL基因第2外显子存在g.355420C＞T和g.355427T＞A 2个突变位点,且都处于中度多态,其中g.355420C＞T位点为本试验新发现的突变位点,g.355427T＞A位点所编码的氨基酸由苏氨酸转变为丝氨酸.基因型与生长性状的关联分析结果表明,g.355420C＞T位点CC基因型个体的体高、体长和体重均显著大于CT和TT基因型个体(P＜0.05),C等位基因对湘西黄牛的生长性状为正效应.g.355427T＞A位点的TT和AT基因型个体的体高、体长、胸围和体重均极显著大于AA基因型个体(P＜0.01),T等位基因为正效应.表明LPL基因第2外显子的g.355420C＞T和g.355427T＞A位点对湘西黄牛生长性状有显著影响,可能为湘西黄牛生长性状的分子遗传标记位点.