基于全基因组填充重测序关联分析鉴别影响苏山猪初生体尺与乳头数性状的遗传位点

旨在鉴别影响苏山猪初生体尺和乳头数性状的遗传位点，开发可用于辅助育种的分子标记，为苏山猪生长和繁殖性能的持续选育提供理论基础。本试验对269头苏山猪初生仔猪(出生后24 h内)的体尺和乳头数表型进行测定，并采集耳组织样品。基于全基因组重测序及基因型填充策略，利用全基因组关联分析(genome-wide association study, GWAS)和群体分化指数(fixation index,Fst)的方法挖掘与目的性状强关联位点，并对位置功能候选基因开展GO和KEGG分析，确定最有可能的主效基因。本研究共鉴别到4个候选位点，分布在13、14和X染色体上，其中与初生体尺性状显著关联的位点有2个，与乳头数性状显著关联的位点有2个。本研究筛选出1个与体长性状相关的候选基因ACTA2;1个与胸围性状相关的候选基因COL4A6;3个与乳头数性状相关的候选基因ACTA2、CRTAP和SEPTIN6,为苏山猪初生体尺性状和乳头数性状的遗传改良提供了重要的分子标记。

An Imputed Whole-genome Sequence-based GWAS Approach Pinpoints Genetic Loci for Body Conformation at Birth and Teat Number Traits in Sushan Pig Population

The purpose of this study was to identify the genetic loci that affected the body conformation at birth and teat number traits, develop molecular markers that can be used for assisted breeding, and provide a theoretical basis for the continuous selection of growth and reproductive performance in Sushan pig population. The phenotype included body conformation at birth and teat number were measured in 269 Sushan newborn piglets (within 24 h after birth), and the ear tissue samples were collected at the same time. Based on whole-genome resequencing and genotype imputation strategy, GWAS and Fst methods were used to identify the significant loci associated with the target traits. GO and KEGG analyses were performed on the positional and functional candidate genes to identify the most likely major genes. A total of 4 candidate loci were identified in this study, located in the 13, 14 and X chromosomes, of which 2 were significantly associated with body conformation at birth traits, and 2 were significantly associated with the teat number traits. This study screened out 1 candidate gene ACTA2 related to the body length, 1 candidate gene COL4A6 related to the chest circumference, and 3 candidate genes ACTA2, CRTAP, and SEPTIN6 related to the teat number. This research provides important molecular markers for the genetic improvement of body conformation at birth and teat number traits in Sushan pig population.