利用AIMs分析亚洲9个绵羊群体的群体结构

Population Structure of 9 Asian Sheep Populations Inferred by AIMs

祖先信息标记(ancestry informative makers,AIMs)可用来分析群体的遗传结构.本研究利用Illumina Ovine SNP50芯片上的SNP位点,在云南乌骨绵羊和其他8个亚洲绵羊群体中以Rosenberg等定义的Informativeness统计量为筛选方法,选取Informativeness值最高的前20、50、100、500个SNP位点与相应数目的随机SNP位点分别用来推断群体的遗传结构.通过主成分分析和用fast STRUCURE推断祖先成分的方法,评价AIMs在推断亚洲绵羊群体遗传结构中的作用.研究显示,利用筛选到的高信息含量标记AIMs,可减少群体结构研究中需要的SNP位点数目.前50个AIMs可有效地将绵羊群体分为4个大类,这与利用全基因组SNPs分析得到的群体结构是一致的,即乌骨绵羊群体blackbone单独为一类、西藏群体changthangi和tibetan归为一类,孟加拉的banglandeshi、banglandeshi Garole群体和印度的Indian Garole群体归为一个类群,其余三个群体(印度尼西亚sumatran、garut群体和印度的deccani群体)近似归为一类.这4大类群在AIMs上存在显著的分化,利用这些位点信息可以为研究群体特征和进化关系提供线索.

Ancestral information Markers（AIMs） can be utilized for analysis of population genetic structure.In this study,AIMs were selected from Illumina Ovine SNP50 chip in blackbone sheep and other eight kinds of Asian sheep populations by Informativeness-statistic defined by Rosenberg.Then subsets of 20,50,100,500 SNPS loci with higher Informativeness value and the corresponding number of random SNP loci were used to infer the population genetic structure,respectively.Principal component analysis（PCA） and fast STRUCURE methods evaluated AIMs＇ role in distinguishing the population structure of these 9 Asian sheep population structure.AIMs screened in our study are usefulness in assigning samples to different genetic groups,helping reducing the number of SNPs in sheep genetic researches.The top 50 AIMs can be used effectively to cluster sheep populations into 4groups,which is consist with the result by the genome-wide SNPs：1）blackbone group,2）changthangi and tibetan group;3）group of banglandeshi,banglandeshi Garole and Indian Garole,4） group of sumatran,garut and deccani.Alleles Frequncies of AIMs are significantly different among these sheep populations,inferring these markers may be useful in the genetic evolution analysis of these 9 sheep population.