利用全基因组高通量SNP标记定位二花脸×沙子岭家系中的断奶体重QTL

Detection of Quantitative Trait Loci for Live Weight at Weaning in an Erhualian×Shaziling Population Using Whole-Genome High-Density SNP Markers

【目的】利用二花脸×沙子岭家系定位影响仔猪45日龄断奶体重的数量性状位点(quantitative trait loci,QTL)并搜寻QTL区间内与表型相关的位置候选基因,为最终鉴别因果基因奠定前期工作基础。【方法】构建二花脸×沙子岭猪F2资源家系,利用Illumina porcine 60k DNA芯片判定F2个体的基因型,对45日龄断奶体重表型进行全基因组连锁分析,定位影响二花脸×沙子岭家系F2家系仔猪45日龄断奶体重的QTL。在Ensemble(EMBL-EBI)和NCBI(National Center for Biotechnology Information)网站基因组数据库中搜寻相应的位置候选基因。【结果】在猪的2号染色体(sus scrofa chromosome 2,SSC2)上定位到了1个5%基因组水平显著的QTL,在猪的5号染色体(sus scrofa chromosome 5,SSC5)和猪的14号染色体(sus scrofa chromosome 14,SSC14)上分别定位到了1个1%基因组水平显著的QTL。在上述3个QTL区域内搜寻到了5个与仔猪45日龄断奶体重相关的候选基因,分别是SSC2上的CYP2R1、COPB1、PDE3B基因和SSC5上的NOP2、GDF3基因。【结论】本研究将影响二花脸×沙子岭家系仔猪45日龄断奶体重的QTL定位于SSC2、SSC5和SSC14,并揭示出5个与仔猪45日龄断奶体重相关的候选基因。

【Objective】An Erhualian×Shaziling F2 resource population was constructed to map quantitative trait loci（QTL） for liveweight of piglets at the weaning age of 45 days and identify positional candidate genes related to weaned liveweight,providing a start pointing to detect the causal genes in the future.【Method】The F2 resource population was constructed and genomic DNA of all weaned piglets was genotyped with Illumina porcine 60 k DNA chip.Whole-genome linkage analysis was conducted to detect QTL for liveweight of piglets weaned at day 45.Positional candidate genes were characterized from Ensemble（EMBL-EBI） and NCBI（National Center for Biotechnology Information） database.【Result】A total of 3 QTLs were detected for the measured phenotype including one 5% genome-wide QTL on sus scrofa chromosome 2（SSC2） and one 1% genome-wide QTL on sus scrofa chromosome 5（SSC5） and sus scrofa chromosome 14（SSC14）,respectively.Five candidate genes were identified,including CYP2R1,COPB1 and PDE3B on SSC2 and NOP2,GDF3 on SSC5.【Conclusion】The QTL for liveweight of piglets weaned at day 45 were mapped on SSC2,SSC5 and SSC14,and 5 positional candidate genes were identified.