Zhang Long-Chao, Yue Jing-Wei, Pu Lei, Wang Li-Gang, Liu Xin, Liang Jing, Yan Hua, Zhao Ke-Bin, Li Na, Shi Hui-Bi, Zhang Yue-Bo, Wang Li-Xian
Key Laboratory of Farm Animal Genetic Resources and Germplasm Innovation of Ministry of Agriculture, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, 100193, China.
Mol Genet Genomics. 2016 Oct;291(5):1885-90. doi: 10.1007/s00438-016-1220-1. Epub 2016 Jun 15.
In China, sparerib is one of the most valuable parts of the pork carcass. As a result, candidate gene mining for number of ribs has become an interesting study focus. To examine the genetic basis for this major trait, we genotyped 596 individuals from an F2 Large White × Minzhu intercross pig population using the PorcineSNP60 Genotyping BeadChip. The genome-wide association study identified a locus for number of ribs in a 2.38-Mb region on Sus scrofa chromosome 7 (SSC7 of Sus scrofa genome assembly, Sscrofa10.2). We identified the top significant SNP ASGA0035536, which explained 16.51 % of the phenotypic variance. A previously reported candidate causal mutation (g.19034 A>C) in vertebrae development-associated gene VRTN explained 8.79 % of the phenotypic variation on number of ribs and had a much lower effect than ASGA0035536. Haplotype sharing analysis in F1 boars localized the rib number QTL to a 951-kb interval on SSC7. This interval encompassed 17 annotated genes in Sscrofa10.2, including the previously reported VRTN candidate gene. Of the 17 candidate genes, LTBP2, which encodes a latent transforming growth factor beta binding protein, was previously reported to indirectly regulate the activity of growth differentiation factor Gdf11, which has been shown to increase the number of ribs in knock-out mice. Thus, we propose LTBP2 as a good new candidate gene for number of ribs in the pig population. This finding advances our understanding of the genetic architecture of rib number in pigs.
在中国，排骨是猪胴体中最有价值的部分之一。因此，对肋骨数量进行候选基因挖掘已成为一个有趣的研究焦点。为了研究这一主要性状的遗传基础，我们使用猪60K SNP基因分型芯片对一个大白猪×民猪F2代杂交群体中的596头个体进行了基因分型。全基因组关联研究在猪7号染色体（猪基因组组装版本Sscrofa10.2中的SSC7）上一个2.38 Mb的区域内鉴定到一个与肋骨数量相关的位点。我们确定了最显著的SNP ASGA0035536，它解释了16.51%的表型变异。先前报道的与椎骨发育相关基因VRTN中的一个候选因果突变（g.19034 A>C）解释了8.79%的肋骨数量表型变异，其效应远低于ASGA0035536。对F1代公猪的单倍型共享分析将肋骨数量QTL定位到SSC7上一个951 kb的区间。该区间在Sscrofa10.2中包含17个注释基因，包括先前报道过的VRTN候选基因。在这17个候选基因中，编码潜在转化生长因子β结合蛋白的LTBP2，先前有报道称其间接调节生长分化因子Gdf11的活性，而Gdf11已被证明在基因敲除小鼠中可增加肋骨数量。因此，我们提出LTBP2是猪群体中肋骨数量的一个新的良好候选基因。这一发现增进了我们对猪肋骨数量遗传结构的理解。
