F_(3)代香苏杂交猪DKK1基因多态性与生长性状的关联性

Correlation analysis of DKK1 gene polymorphism and growth traits of F_(3) generation Xiangsu hybrid pigs

【目的】筛选出F_(3)代香苏杂交猪Dickkopf-1基因(DKKI)的单核苷酸多态性位点(SNPs),并分析基因多态性与生长性状的关联性,为培育香苏杂交猪新品系提供参考依据,同时为深入研究DKK1基因生物学功能打下基础。【方法】通过DNA混池测序的方法对164头F_(3)代香苏杂交猪群体DKK1基因进行SNPs鉴定,采用Excel 2017计算不同基因型的基因频率、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),以卡方(χ;)检验分析基因型是否处于Hardy-Weinberg平衡状态,并在此基础上分析F_(3)代香苏杂交猪SNPs位点与生长性状的关联性。【结果】在F_(3)代香苏杂交猪DKK1基因的Exon-3,4区域发现6个SNPs位点,分别是A2010T、G2012C、C2014T、A2040C、C2042A和G2044C。6个SNPs位点的Ho均高于He,其中,A2010T、G2012C、A2040C、C2042A和G2044C等5个SNPs位点的PIC处于中度多态水平,C2014T位点的PIC则处于低度多态水平。χ;检验结果表明,仅C2042A位点处于Hardy-Weinberg极度不平衡状态(P<0.01),其他5个SNPs位点(A2010T、G2012C、C2014T、A2040C和G2044C)均处于Hardy-Weinberg平衡状态(P>0.05)。关联分析结果表明,F_(3)代香苏杂交猪DKK1基因A2010T、G2012C、C2014T、A2040C和G2044C位点的不同基因型在体高、胸围、管围、胸深和腿臀围方面表现出差异显著(P<0.05)或极显著(P<0.01)。【结论】F_(3)代香苏杂交猪DKK1基因A2010T、G2012C、C2014T、A2040C和G2044C位点不同基因型与体高、胸围、管围、胸深和腿臀围呈显著或极显著相关,可作为培育新品系的主效候选基因或与主基因紧密连锁的分子标记。

【Objective】Single nucleotide polymorphisms(SNPs)of the Dickkopf-1(DKKI)gene of the F_(3)generation Xiangsu hybrid pigs were screened out,and the correlation between the gene polymorphism and growth traits was analyzed,in order to cultivate a new line of Xiangsu hybrid pigs,so as to lay a foundation for in-depth study on the biological function of DKK1 gene.【Method】SNPs of DKK1 gene in 164 F_(3)generation Xiangsu hybrid pig populations were identified by DNA mixed pool sequencing.Gene frequency,genotype frequency,genetic homozygosity(Ho),expected heterozygosity(He),effective allele number(Ne)and polymorphic information content(PIC)of different genotypes were calculated by Excel 2017.Chi square(χ~2) test was used to analyze whether the genotypes were in Hardy-Weinberg equilibrium,then the association between SNPs and growth traits in F_(3)Xiangsu hybrid pigs was analyzed based on it.【Result】Six SNPs were found in Exon-3,4 region of DKK1 gene of F_(3)Xiangsu hybrid pigs,which were A2010T,G2012C,C2014T,A2040C,C2042A and G2044C respectively.Ho of the six SNPs was higher than that of He.The PIC of the five SNPs,A2010T,G2012C,A2040C,C2042A and G2044C was at the moderate polymorphism level,while the pic of C2014T was at the low polymorphism level.χ~2 test results showed that only C2042A locus was in Hardy-Weinberg extreme disequilibrium state(P<0.01),and the other five SNPs loci(A2010T,G2012C,C2014T,A2040C and G2044C)were in Hardy-Weinberg equilibrium state(P>0.05).The results of association analysis showed that different genotypes of DKK1 gene A2010T,G2012C,C2014T,A2040C and G2044C in F_(3)generation Xiangsu hybrid pigs showed significant differences in body height,chest circumference,tube circumference,chest depth or leg and hip circumference(P<0.05)or extremely significant(P<0.01).【Conclusion】Different genotypes at A2010T,G2012C,C2014T,A2040C and G2044C of DKK1 gene in F_(3)Xiangsu hybrid pigs are significantly or extremely significantly correlated with body height,chest circumference,tube circumference,chest depth orleg and hip circumference,which can be used as the main candidate gene or molecular markers closely linked with the main genes for breeding new lines.