松辽黑猪METTL23基因多态性及其与繁殖性状的关联分析

为探究松辽黑猪METTL23基因多态性及其与繁殖性状的关联性,试验选取178头松辽黑猪母猪为研究对象,利用Sanger直接测序法查找METTL23基因外显子1~5的单核苷酸多态性(SNP),使用SPSS 19.0软件分析METTL23基因SNP位点与松辽黑猪繁殖性状(总产仔数、产活仔数、断奶仔猪数、初生重、3周龄重、断奶重、乳头数)的关联性。结果显示,仅在松辽黑猪METTL23基因外显子4发现1个SNP位点,命名为A62G,在A62G位点上检测到3种基因型,分别是AA、AG和GG。GG和G分别为优势基因型和优势等位基因,且A62G位点处于Hardy-Weinberg平衡状态(P>0.05)。该位点的遗传纯合度(Ho)为0.6516,高于遗传杂合度(He,0.3484),说明其在松辽黑猪群体中的变异较小;多态信息含量(PIC)为0.2877,属于中度多态位点(0.25<PIC<0.5),说明该遗传标记能够提供一定量的遗传信息。关联分析结果表明,GG基因型个体总产仔数、产活仔数和断奶仔猪数均显著或极显著高于AA基因型个体(P<0.05;P<0.01),总产仔数还显著高于AG基因型个体(P<0.05);AG基因型个体断奶仔猪数显著高于AA基因型个体(P<0.05);初生重、3周龄重、断奶重、乳头数各基因型间差异均不显著(P>0.05)。综上所述,METTL23基因外显子4存在多态性位点A62G,该位点与松辽黑猪产仔数存在显著关联,可作为松辽黑猪产仔数的遗传标记,用于分子育种。

Polymorphism of METTL23 Gene and Its Association with Reproductive Traits in Songliao Black Pigs

In order to investigate the polymorphism of METTL23 gene and its association with reproductive traits in Songliao Black pig.178 Songliao Black sows were selected as the research objects.The single nucleotide polymorphisms (SNPs) of exons 1-5 of METTL23 gene were screened by Sanger direct sequencing, and the correlation between SNP of METTL23 gene and reproductive traits (total number born, number born alive, birth weight, 3-week weight, weaning weight, weaning piglet number and nipple number) were analyzed by using SPSS 19.0 software.The results showed that only one SNP site (named A62G) was found in exon 4 of METTL23 gene in Songliao Black pig.There were three genotypes (AA, AG and GG) in the research population.GG and G were dominant genotype and allele, which was in Hardy-Weinberg balanced (P>0.05).The genetic homozygosity (Ho) of this locus was 0.6516 which was higher than that of genetic heterozygosity (He) of 0.3484, indicating that it had little variation in the population of Songliao Black pigs.The polymorphism information content (PIC) was 0.2877, which belonged to moderate polymorphism (0.25<PIC<0.5), indicating that the genetic marker could provide a certain amount of genetic information.Correlation analysis results showed that the total litter size, live litter size and weaned piglets of GG genotype were significantly or extremely significantly higher than those of AA genotype (P<0.05; P<0.01), and the total litter size was also significantly higher than that of AG genotype individuals (P<0.05).The number of weaned piglets in AG genotype was significantly higher than that in AA genotype (P<0.05).There were no significant differences among genotypes in birth weight, 3-week-old weight, weaning weight and nipple number (P>0.05).In conclusion, there was a SNP site A62G in exon 4 of METTL23 gene, which was significantly correlated with the litter size and might be a genetic marker for litter size in Songliao Black pig molecular breeding.