Since Darwin, evolutionary biologists have sought to understand the drivers and mechanisms of natural trait diversity. The field advances toward this goal with the discovery of phenotypes that vary in the wild, their relationship to ecology, and their underlying genes. Here, we established resistance to extreme low temperature in the free-living nematode Caenorhabditis briggsae as an ecological and evolutionary model system. We found that C. briggsae strains of temperate origin were strikingly more cold-resistant than those isolated from tropical localities. Transcriptional profiling revealed expression patterns unique to the resistant temperate ecotype, including dozens of genes expressed at high levels even after multiple days of cold-induced physiological slowdown. Mutational analysis validated a role in cold resistance for seven such genes. These findings highlight a candidate case of robust, genetically complex adaptation in an emerging model nematode, and shed light on the mechanisms at play.

中文翻译：

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适应当地的线虫种群的寒冷生存及其分子机制


自达尔文以来，进化生物学家一直试图了解自然性状多样性的驱动因素和机制。通过发现野生环境中不同的表型、它们与生态的关系以及它们的潜在基因，该领域朝着这一目标前进。在这里，我们建立了自由生活的线虫对极端低温的抵抗力作为生态和进化模型系统。我们发现源自温带的 C. briggsae 菌株比热带地区分离的菌株具有惊人的耐寒性。转录谱揭示了抗性温带生态型特有的表达模式，包括即使在寒冷引起的生理减缓多天后，数十个基因仍以高水平表达。突变分析验证了七个此类基因在抗寒性中的作用。这些发现突出了新兴模型线虫中强大的、遗传复杂的适应性的候选案例，并揭示了其中的机制。