绵羊GLP2R基因多态性及其与肉质性状的相关分析

为探索胰高血糖素样肽-2受体（glucagon-like peptide-2 receptor，GLP2R）基因多态性与绵羊肉质性状的相关性，试验选用68只南非肉用美利奴羊×东北细毛羊和102只杜泊羊×小尾寒羊的杂交后代为研究对象，采用Sanger测序方法寻找GLP2R基因外显子11序列的突变位点，根据测序结果分析该突变位点的基因型频率和基因频率及卡方适合性检验、纯合度（Ho）、杂合度（He）和多态信息含量（PIC）。结果显示，绵羊GLR2R基因外显子11处存在C/T突变，存在3种基因型：CC、TC和TT，2种等位基因：C和T，其中在南非肉用美利奴羊×东北细毛羊群体中，TC基因型为优势基因型，在杜泊羊×小尾寒羊群体中，CC基因型为优势基因型；2个群体中C均为优势等位基因。卡方适合性检验结果显示，2个群体的C/T位点均处于Hardy-Weinberg平衡状态（P>0.05）；C/T突变位点在群体内变异较小且处于中度多态（0.25 < PIC < 0.5），有一定遗传学意义。不同基因型肉质性状差异结果显示，南非肉用美利奴羊×东北细毛羊TC基因型剪切力显著高于CC和TT基因型，TT基因型失水率显著高于CC和TC基因型（P<0.05）；杜泊羊×小尾寒羊CC基因型剪切力显著高于TC和TT基因型，TT基因型失水率显著高于CC和TC基因型（P<0.05）。本研究在GLP2R基因外显子处发现C/T突变，可能是影响肉质性状的潜在位点，是否能够作为遗传标记还需要进一步探索。

Correlation Analysis Between GLP2R Gene Polymorphism and Meat Quality Traits in Sheep

To explore the correlation between glucagon-like peptide-2 receptor (GLP2R) gene polymorphism and meat quality traits in sheep,the hybrid offspring of 68 South African meat Merino sheep×Northeast Fine wool sheep and 102 Dorper sheep×Small-tail Han sheep as the research object in this study,the Sanger sequencing method was used to find the mutation sites of the sequences of GLP2R gene exon 11,according to the sequencing results,the genotype frequency and gene frequency of the mutation site and the chi-square suitability test,homozygosity (Ho),heterozygosity (He) and polymorphism information content (PIC) were analyzed.The results showed that there were C/T mutations of GLR2R gene exon 11 in sheep,there were three genotypes (CC,TC and TT) and two alleles (C and T).TC genotype was the dominant genotype in South Africa meat Merino sheep×Northeast Fine wool sheep,CC genotype was the dominant genotype in Dorper sheep×Small-tail Han sheep,and C allele was dominant in both two populations.The results of chi-square suitability test showed that C/T site in two populations were in Hardy-Weinberg equilibrium (P>0.05).The intra-population variation was small and moderate polymorphism (0.25 < PIC < 0.5),which had certain genetic significance.The results of different genotypes of meat quality traits showed that the shearing force of TC genotype in South African meat Merino sheep×Northeast Fine wool sheep was significantly higher than that of CC and TT genotypes,and the water loss rate of TT genotype was significantly higher than that of CC and TC genotypes (P<0.05);The shearing force of CC genotype in Dorper sheep×Small-tail Han sheep was significantly higher than that of TC and TT genotypes,and the water loss rate of TT genotype was significantly higher than that of CC and TC genotypes (P<0.05).In this study,a C/T mutation was found in GLP2R gene exon,which might be a potential site affecting meat quality traits,whether it could be used as a genetic marker needed further exploration.