雷州山羊TBX 15基因多态性及其与体尺性状的关联分析

Polymorphism of TBX 15 Gene and Its Association Analysis with Body Size Traits in Leizhou Goats

【目的】本研究旨在筛查雷州山羊T盒子转录因子15(TBX15)基因潜在的单核苷酸多态性(SNP)位点,并分析其与体尺性状的关联性,为雷州山羊分子选育提供理论支撑。【方法】采集78只雷州山羊血样提取基因组DNA,利用PCR扩增和直接测序法检测TBX 15基因SNP位点,并分析其遗传多样性;采用SPSS 23.0软件分析TBX 15基因多态性与雷州山羊体高、体长和胸围等体尺性状的关联性;利用HaploView软件进行TBX 15基因SNP位点的连锁不平衡和单倍型分析。【结果】在雷州山羊TBX 15基因内含子上发现3个SNPs位点:g.96346139 A>G、g.96345894 T>C和g.96330058 G>A,均存在3种基因型,优势基因型分别为GG、CC和AA;卡方检验结果表明,其均处于Hardy-Weinberg平衡状态;多态信息含量(PIC)分别为0.309、0.285及0.294,均为中度多态(0.25<PIC<0.50)。关联分析结果发现,雷州山羊TBX 15基因g.96346139 A>G位点GG基因型个体的体高、十字部高和体斜长均显著高于AA基因型(P<0.05);g.96345894 T>C位点CC基因型个体的体高、十字部高、体斜长和胸深均显著高于TT基因型(P<0.05);g.96330058 G>A位点GG基因型个体的胸深显著低于其他2种基因型(P<0.05)。在单倍型和连锁不平衡分析中发现,3个SNPs位点间存在强连锁关系(R 2>0.33),有5种主要单倍型,其中优势单倍型是ACG,其概率为0.716。【结论】雷州山羊TBX 15基因3个SNPs位点对体高、体斜长等体尺指标具有显著影响,且该3个位点间具有强连锁关系,单倍型ACG可作为雷州山羊选育的候选标记。

【Objective】The aim of this study was to screen the potential single nucleotide polymorphism(SNP)of T-box transcription factor 15(TBX15)gene and analyze its correlation with body size traits in Leizhou goats,so as to provide theoretical support for molecular breeding of Leizhou goats.【Method】DNA were extracted from blood samples of 78 Leizhou goats.TBX 15 gene SNP was detected by PCR amplification and direct sequencing,and its genetic diversity was analyzed.The correlation between the polymorphism of TBX 15 gene and body size traits such as body height,body length and chest circumference in Leizhou goats were analyzed using SPSS 23.0 software.The linkage disequilibrium and haplotype of TBX 15 gene SNP were analyzed by HaploView software.【Result】Three SNPs were found on the intron of TBX 15 gene,namely g.96346139 A>G,g.96345894 T>C and g.96330058 G>A.There were three genotypes in all the three SNPs,and the dominant genotypes were GG,CC and AA,respectively.The chi-square test indicated that three SNPs were all in Hardy-Weinberg equilibrium,the polymorphic information content(PIC)were 0.309,0.285 and 0.294,respectively,indicating moderate polymorphism(0.25<PIC<0.50).The association analysis results showed that the body height,cross height and body length of GG genotype at g.96346139 A>G of TBX 15 gene in Leizhou goats were significantly higher than those of AA genotype(P<0.05).The body height,cross height,body length and chest depth of CC genotype at g.96345894 T>C of TBX 15 gene were significantly higher than those of TT genotype(P<0.05).The chest depth of GG genotype at g.96330058 G>A of TBX 15 gene was significantly lower than that of the other two genotypes(P<0.05).In the analysis of haplotypes and linkage disequilibrium,it was found that there was a strong linkage relationship among three SNPs(R 2>0.33),with five main haplotypes,among which the dominant haplotype was ACG,with a probability of 0.716.【Conclusion】Three SNPs of TBX 15 gene in Leizhou goats had significant effects on body height,body length and other body size indicators,and the three SNPs were in linkage disequilibrium with a strong linkage relationship.Haplotype ACG could serve as candidate markers in Leizhou goat breeding.