基于SNP芯片撒坝猪保种群体的遗传结构分析

Genetic structure analysis of a conserved population of Saba pigs based on SNP chips

试验旨在从分子水平分析撒坝猪保种群体的遗传结构变化以及遗传多样性,拓宽遗传背景,指导和促进撒坝猪的保种工作。利用“京芯一号”SNP 芯片对云南省楚雄州种猪场 100 头保种撒坝猪群体的 DNA 进行遗传群体结构分析。结果表明:撒坝猪保种群体的有效群体含量(Ne)为 21,群体的多态性标记比例(PN)为 0.533,群体的期望杂合度(He)为 0.263,观察杂合度(Ho)为 0.275;G 矩阵表明公畜与母畜之间基因组亲缘关系呈中等;100 头撒坝猪保种群体可分为 A ~ G 7 个家系;在 100 头撒坝猪保种群体中,共检测到 3552 个长纯合片段(ROH),长度在 8.20 ~621.32 Mb,每头撒坝猪含有 2 ~ 53 个 ROH,且平均个体 ROH 长度为(319.38±111.39)Mb。该撒坝猪保种群体基于ROH 的近交系数(F_(ROH))平均为 0.130,中位数大于 0.125。本研究表明,该保种撒坝猪群体内家系数量适中,个别家系公畜数量较少,各家系个体数差异明显,群体中可能存在非撒坝猪的外来血缘,个体亲缘关系呈中等程度,近交程度较高,需要进行合理选配或者从原种场引入新的血统方式来确保撒坝猪遗传资源的多样性。

The experiment aimed to analyse the genetic structure chang es and genetic diversity of the conserved Saba pig population at the molecular level,to broaden the genetic background,and to guide and promote the conserving work of Saba pigs.The DNA of 100 conserved Saba pig populations from Chuxiong breeding farms in Yunnan province was analysed for genetic population structure using the “Jingxin-1” SNP chip.The results showed that the effective population content (Ne) of the conserved Saba pig population was 21,the polymorphic marker ratio (PN) of the population was 0.533,the expected heterozygosity (He) of the population was 0.263 and the observed heterozygosity (Ho) was 0.275;the G matrix indicated that the genomic affinity between the male and female animals was moderate;the 100 conserved Saba pig population could be divided into 7 families from A ~ G.A total of 3552 runs of homozygosity (ROH),ranging from 8.20 ~621.32 Mb in length,were detected in the conserved population of 100 Saba pigs,with 2 ~ 53 ROH per Saba pig and an average individual ROH length of (319.38±111.39)Mb.The median inbreeding coefficient (F_(ROH))was 0.130,with a median of more than 0.125.This study indicated that the number of lines in the conserved Saba pig population was moderate,with a small number of males in individual lines and significant differences in the number of individuals in each line,and that there may be non -Saba pigs of foreign origin in the population,with a moderate degree of individual relatedness and a high degree of inbreeding.It was necessary to ensure the diversity of the genetic resources of the Saba pigs by reasonable selection or introduction of new pedigrees from the original breeding farms.