F3代波杂山羊XKR4基因多态性与生长性状的关联分析

【目的】明确F₃代波杂山羊XKR4基因多态性与生长性状的关联性，筛选出优异基因为后期培育新品系提供理论依据。【方法】以F₃代波杂山羊为研究对象，通过血液DNA混池测序鉴定XKR4基因SNP位点，统计SNP位点的等位基因频率、基因型频率、遗传纯合度（Ho）、期望杂合度（He）、有效等位基因数（Ne）及多态信息含量（PIC）等，以卡方（χ2）检验分析基因型是否处于Hardy-Weinberg平衡状态，并利用SPSS 25.0分析不同基因型与F₃代波杂山羊生长性状的关联性。【结果】 F₃代波杂山羊XKR4基因Intron-1区域存在2个SNPs位点，分别是C194069A和T194091A。C194069A位点的等位基因频率中C>A，优势基因型为CC型； T194091A位点的等位基因频率中T>A，优势基因型为TT型；C194069A和T194091A位点均处于Hardy-Weinberg平衡（P>0.05）。关联分析结果表明:在初生群体中，T194091A位点AA基因型与其他基因型的体斜长存在显著差异（P<0.05，下同）；在3月龄群体中，C194069A和T194091A位点各基因型的生长性状指标间均无显著差异（P>0.05，下同）；在6月龄群体中，C194069A和T194091A位点AA基因型的体重分别与相应位点的CC基因型和TT基因型存在显著差异；在12月龄群体中，C194069A位点AA基因型在体重和胸围方面均极显著优于CC基因型（P<0.01，下同），在体高方面与CC基因型存在显著差异，T194091A位点AA基因型的体重、体斜长分别与TT基因型呈显著或极显著差异。此外，在0~6月龄和0~12月龄，C194069A和T194091A位点AA基因型的日增重与CC基因型和TT基因型分别存在呈显著或极显著差异。【结论】 F3代波杂山羊XKR4基因存在2个SNPs位点（C194069A和T194091A），且均表现为AA基因型个体的生长性能优于其他基因型个体，即XKR4基因可作为F₃代波杂山羊生长性状的候选基因。

Correlation analysis of XKR4 gene polymorphism and growth traits in F3 generation Boza goats

【Objective】 To identify the correlation between XKR4 gene polymorphism and growth traits of F₃ generation Boza goats，and screen out excellent genes to provide theoretical basis for the later development of new strain.【Method】 Taking F₃ generation Boza goats as materials，and the SNP sites of XKR4 gene were identified by blood DNA mixed pool sequencing.SNP sites’allele frequency，genotype frequency，genetic homozygosity（Ho），expected heterozygosity （He），effective number of alleles（Ne）and polymorphic information content（PIC）of SNP sites were counted.Chisquare（χ2）test was used to analyze whether the genotypes were in Hardy-Weinberg equilibrium state，and SPSS 25.0 was used to analyze the association between different genotypes and growth traits of F₃ generation Boza goats.【Result】 There were 2 SNP sites in intron-1 region of XKR4 gene in F₃ generation Boza goats，namely C194069A and T194091A.The allele frequency of C194069A was C>A，and the dominant genotype was CC；the allele frequency of T194091A was T>A ，and the dominant genotype was TT；C194069A and T194091A were in Hardy-Weinberg equilibrium（P>0.05）.Association analysis showed that there were significant differences in body oblique length between AA genotype at T194091A locus and other genotypes in the primary population（P<0.05，the same below）.In the 3-month-old population，there were no significant differences in the growth traits of C194069A and T194091A genotypes（P>0.05）.In the 6-month-old population，the body weight of AA genotype at C194069A and T194091A was significantly different from that of CC genotype and TT genotype at corresponding loci，respectively.In the 12-month-old population，AA genotype at C194069A was extremely significantly superior to CC genotype in weight and chest circumference（P<0.01，the same below） ，but it had significant differences from CC genotype in body height.AA genotype at T194091A locus had significant or extremely significant differences in weight and body length from TT genotype.In addition，daily gains of AA genotypes at C194069A and T194091A were extremely significantly or significantly different from CC and TT genotypes in 0-6 months and 0-12 months of age populations，respectively.【Conclusion】XKR4 gene in F₃ generation Boza goats had 2 SNP sites，and the growth performance of AA genotype individuals was better than that of other genotypes in F₃ generation of Boza goats，indicating that XKR4 gene can be used as a candidate gene for growth traits of F₃ generation of Boza goats.