Department of Ecology and Evolutionary Biology, Brown University, Providence, RI 02912, USA.
Science. 2011 Oct 7;334(6052):86-9. doi: 10.1126/science.1209271.
Local adaptation is critical for species persistence in the face of rapid environmental change, but its genetic basis is not well understood. Growing the model plant Arabidopsis thaliana in field experiments in four sites across the species' native range, we identified candidate loci for local adaptation from a genome-wide association study of lifetime fitness in geographically diverse accessions. Fitness-associated loci exhibited both geographic and climatic signatures of local adaptation. Relative to genomic controls, high-fitness alleles were generally distributed closer to the site where they increased fitness, occupying specific and distinct climate spaces. Independent loci with different molecular functions contributed most strongly to fitness variation in each site. Independent local adaptation by distinct genetic mechanisms may facilitate a flexible evolutionary response to changing environment across a species range.
面对快速的环境变化，本地适应对于物种的生存至关重要，但它的遗传基础还不是很清楚。我们在该物种的原生范围的四个地点进行了田间实验，让模式植物拟南芥生长，通过对来自不同地理区域的拟南芥全基因组关联研究，确定了与本地适应相关的候选基因座。适应相关的基因座表现出地理和气候上的本地适应特征。与基因组对照相比，高适应性等位基因通常分布在增加适应性的地点附近，占据特定而独特的气候空间。在每个地点，具有不同分子功能的独立基因座对适应性变化的贡献最大。不同遗传机制的独立的本地适应可能有助于物种范围内对不断变化的环境做出灵活的进化反应。
