民猪保种群体的遗传基础分析

Genetic basis analysis of min pig breed preservation population

为了科学准确地划分现有民猪保种群体的亲缘关系及家系结构,试验采用猪的"中芯一号"育种芯片检测了70头民猪的单核苷酸多态性(single nucleotide polymorphism, SNP);使用MEGAX(V10.0)和R软件进行公畜样本及全部样本的聚类分析,使用Plink(V1.90)和R软件等进行近交系数的计算及因果突变分析,并统计分析影响猪的肉质性状、生长和体型性状、繁殖性状和抗病性性状等11个基因的基因型。结果表明:民猪保种群内的20头公猪可划分为5个血统,49头母猪可分别划入这5个血统,但有1头个体与这5个血统均不存在亲缘关系,而被归为"其他"。群体平均近交系数为0.11,属于中度近交。在因果突变分析中,该群体内氟烷基因和酸肉基因还未得到净化;采食量、抗仔猪腹泻和料肉比的优势等位基因占比较高,但影响多肋骨数和多胸椎数的优势等位基因占比非常低,还有较大的选择空间。说明未来该民猪保种群体要尽量避免近交,考虑引入新的公猪血统,尽快剔除携带有劣势基因型的个体,提升种群的生产性能。

In order to scientifically and accurately classify the genetic relationship and pedigree structure of the existing conservation Min pig, ‘No.1 Zhongxin’ porcine breeding chip was used to detect the single nucleotide polymorphism(SNP) of 70 Min pigs. Megax(V10.0) and R software were used for cluster analysis of male samples and both samples. Plink(V1.90), R software and other soft wares were used for calculation of inbreeding coefficient(runs of homozygosity, FROH) and the analysis of causal mutation sites. Genotypes of 11 genes affecting meat quality traits, growth and body shape traits, reproductive traits and disease resistance traits of pigs were analyzed. The results showed that 20 boars in the population could be divided into 5 bloodlines, and 49 sows could be assigned to the 5 bloodlines, but one individual was not related to any of the five lineages and was classified as ‘other’. The average inbreeding coefficient of this population was 0.11, belonging to moderate inbreeding. In the detection of causal mutation sites, the fluoralkyl gene and sour meat gene in this population had not been purified. The dominant alleles of feed intake, anti-piglet diarrhea and feed conversion ratio were relatively high, but the dominant alleles of rib number and thoracic vertebra number were very low, so there was still a big space for choice. The results indicated that this Min pig conservation population inbreeding should be avoided as much as possible in the future, the introduction of external blood should be considered, and the individuals carrying inferior genotypes should be eliminated as soon as possible to improve the production performance of the population.