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.