Sutter Nathan B, Bustamante Carlos D, Chase Kevin, Gray Melissa M, Zhao Keyan, Zhu Lan, Padhukasahasram Badri, Karlins Eric, Davis Sean, Jones Paul G, Quignon Pascale, Johnson Gary S, Parker Heidi G, Fretwell Neale, Mosher Dana S, Lawler Dennis F, Satyaraj Ebenezer, Nordborg Magnus, Lark K Gordon, Wayne Robert K, Ostrander Elaine A
National Human Genome Research Institute, Building 50, Room 5349, 50 South Drive MSC 8000, Bethesda, MD 20892-8000, USA.
Science. 2007 Apr 6;316(5821):112-5. doi: 10.1126/science.1137045.
The domestic dog exhibits greater diversity in body size than any other terrestrial vertebrate. We used a strategy that exploits the breed structure of dogs to investigate the genetic basis of size. First, through a genome-wide scan, we identified a major quantitative trait locus (QTL) on chromosome 15 influencing size variation within a single breed. Second, we examined genetic variation in the 15-megabase interval surrounding the QTL in small and giant breeds and found marked evidence for a selective sweep spanning a single gene (IGF1), encoding insulin-like growth factor 1. A single IGF1 single-nucleotide polymorphism haplotype is common to all small breeds and nearly absent from giant breeds, suggesting that the same causal sequence variant is a major contributor to body size in all small dogs.
家犬在体型上表现出比其他任何陆生脊椎动物都更大的多样性。我们采用了一种利用犬类品种结构的策略来研究体型的遗传基础。首先，通过全基因组扫描，我们在15号染色体上鉴定出一个主要的数量性状位点（QTL），它影响单一品种内的体型变异。其次，我们检查了小型和大型品种中QTL周围15兆碱基区间内的遗传变异，发现了跨越单个基因（IGF1，编码胰岛素样生长因子1）的选择性清除的显著证据。一个单一的IGF1单核苷酸多态性单倍型在所有小型品种中都很常见，而在大型品种中几乎不存在，这表明相同的因果序列变异是所有小型犬体型的主要决定因素。
