大白猪MC4R、CDC16基因多态性及其与生长性状的关联分析

Association Between Polymorphism of MC4R and CDC16 Genes and Growth Traits in Large White Pigs

本研究旨在利用高分辨率熔解曲线(high resolution melt,HRM)分型方法检测大白猪黑素皮质素受体(melanocortin-4 receptor,MC4R)和细胞分裂周期蛋白16(cell division cycle 16,CDC16)基因的多态性,并对其与大白猪的生长性状进行关联性分析。试验共采集246头大白猪的耳组织样提取基因组DNA,对小群体样本进行PCR扩增后,通过测序方法寻找两个基因在该群体中的多态性位点,针对已发现的多态性位点设计HRM专用引物,利用HRM方法对大群体进行多态性检测,将所得结果与大白猪生长性状进行关联性分析。结果表明,在MC4R基因序列中检测到1个突变位点2207A>G,2个等位基因:A和G,3个基因型:AA、AG和GG;在CDC16基因第18外显子上检测到了1个突变位点837T>C,2个等位基因:T和C,2种基因型:TT和CT。χ~2适合性检验结果显示,2个基因的基因型频率和等位基因频率在2个种群中分布差异不显著,符合Hardy-Weinberg平衡定律(P>0.05)。多态信息含量(PIC)分析显示,MC4R基因在2个群体中均处于中度多态(0.25<PIC<0.5),而CDC16基因在2个群体中均处于低度多态(PIC<0.25)。关联分析结果发现,MC4R基因对大白猪体重及日增重具有显著影响(P<0.05),CDC16基因对大白猪体高、体长和体重等均具有显著影响(P<0.05)。综上所述,MC4R与CDC16基因对大白猪的生长发育具有一定的影响,为后续大白猪肉质性状与生长性状的现代分子选育提供参考。

This study was aimed to detect the polymorphism of melanocortin-4 receptor (MC4R) and cell division cycle protein 16 (CDC16) in Large White pigs by HRM typing,and analyze its association with growth traits in Large White pigs.A total of 246 Large White pigs ear tissues were collected as research objects,DNA was extracted using the AxyPrep Genomic DNA Extraction Kit.After PCR amplification of small population samples,the polymorphic positions of MC4R and CDC16 genes in the population were searched by sequencing.According to the findings,the polymorphic sites were designed for HRM-specific primers.The HRM method was used to detect the polymorphism in large populations,and the results were correlated with growth traits in Large White pigs.The results showed that one mutation site 2207A>G,two alleles (A and G) and three genotypes (AA,AG and GG) were detected in the MC4R gene sequence.There was a mutation site 837T>C,two alleles (T and C),two genotypes (TT and CT) in the 18th exon of CDC16 gene.The χ^2 test results showed that the genotype frequency and gene frequency of MC4R and CDC 16 genes were not significant difference between the two populations,which was consistent with the Hardy-Weinberg equilibrium (P>0.05).The polymorphic information content (PIC) result showed that MC4R gene was moderate polymorphic (0.25<PIC<0.5),and CDC16 gene was low polymorphic (PIC<0.25) in both populations.The correlation analysis results showed that MC4R gene had significant effects on body weight and daily gain in Large White pigs (P<0.05), CDC16 gene had significant effects on body height,body length and body weight (P<0.05).In summary,MC4R and CDC16 genes had certain effects on the growth and development of Large White pigs,which provided a reference for the modern molecular breeding of meat quality and growth traits in Large White pigs.