【摘要】 旨在挖掘控制绵羊尾型的候选基因,揭示绵羊尾部脂肪沉积机理。本研究利用呼伦贝尔羊两个不同尾型品系的288个个体,其中大尾羊142只和小尾羊146只,基于Illumina Ovine SNP 600KSNP芯片数据计算全基因组单点F_ST值。通过三次光滑样条估计方法确定可变窗口大小和数量,构建W统计量并进行统计检验,鉴定选择区段和注释相关基因。结果,在基因组范围内共确定了23 144个可变窗口,其中区间最大的窗口位于chr12:35 241 750⁴3 798 950bp处,其大小为8.56 Mb,并包含775个SNPs。经检测发现,27个窗口达到极显著水平（P<0.001）,并鉴定了337个候选基因,其中22个是与已发现的脂肪代谢相关的基因。通过GO分析发现,这些候选基因主要富集在细胞内组成成分、有机氮化合物代谢过程以及小分子代谢过程等条目。通过可变窗口F_ST法能够有效检测到受选择的基因与绵羊尾部脂肪沉积相关。这些基因可以作为绵羊尾型选育的候选基因,为培育短尾绵羊提供重要依据。更多还原

【Abstract】 The aims of this study were to reveal the genetic mechanism of fat deposition in the tail of sheep,and to explore the candidate genes involved in sheep tail fat.A total of 288 individuals from two lines of Hulun Buir sheep with different tail types were used to identify candidate genes controlling different tail types of sheep.These individuals included 142 fat-tailed and 146 thintailed sheep.The whole-genome single locus F_ST values were calculated based on the Illumina Ovine 600 KSNP genotype data.The cubic smoothing spline method was used to define the numbers and sizes of variable windows.A total of 23 144 variable windows were identified within the whole genome.The largest window with 775 SNPs was located at chr12:35 241 750-43 798 950 bp,with a size of 8.56 Mb.The W statistic was constructed to detect the windows with selection signature.Twenty-seven of variable windows reached extremely significant level（P<0.001）.After annotation,these windows harbored 337 candidate genes,of which 22 were related to thefat metabolism.Through GO analysis,these candidate genes were mainly enriched in the intracellular components,organonitrogen compound metabolic process and small molecule metabolic process.The F_ST method with variable windows was used to effectively identify candidate genes associated with fat deposition in the tail of sheep.These genes can be used to breed a new sheep breed with small size.The results will provide an important reference for breeding short-tailed sheep.更多还原