The Genetic Basis of Adaptation to Climatic Stress in Siberian Indigenous Populations

我们的物种起源于非洲，随后扩散到除南极洲以外的所有其他大陆。在这次迁徙期间，人类人口暴露在各种气候中，这些气候与他们非洲家园的气候有很大不同。没有任何地方的气候条件比西伯利亚最北端的地区差异更大。事实上，除了日本猕猴之外，人类是唯一一种已经适应了北方环境的灵长类物种--那里的气温在一年中有超过一半的时间保持在远低于冰点的水平--这表明巨大的选择压力可能推动了产生和保存热量的生理过程的加强。然而，尽管人类几千年来一直生活在寒冷的气候中，但我们仍然对这种适应过程是如何在基因水平上发生的知之甚少。西伯利亚的本地种群为研究抗寒的遗传基础提供了最好的机会，因为它们长期居住在地球上一些最寒冷的气候中。虽然北欧的大部分地区在上一次冰川时期都处于冰层之下，但西伯利亚仍然相对没有冰，考古证据表明，人类在这一地区居住了4万多年。人类对这一地区的成功长期定居无疑需要多重适应，以应对持续的严寒胁迫、光周期的剧烈变化以及有限和高度可变的食物资源。该项目将收集15个种群的全基因组多态数据，这些种群生活在西伯利亚大片地区，从西伯利亚南部地区到北极圈内泰米尔半岛最北部的定居点。这些适应寒冷的种群的变异模式将与生活在较温暖气候的中亚和东亚种群的变异模式进行比较。将特别关注基因组区域，这些区域包含以前被认为与冷适应有关的基因，或者在与能量代谢或冷适应特征有关的已知途径中发挥作用的基因。密集的遗传数据、广泛的地理人口覆盖范围，以及几种检测自然选择特征的强大方法的结合，将提供迄今为止人类对寒冷的遗传适应的最全面的图景。

Our species originated in Africa, and subsequently dispersed to all other continents except Antarctica. During this dispersal, human populations were exposed to a variety of climates that differed substantially from those in their African homeland. Nowhere do these climatic conditions differ more dramatically than in the far northern reaches of Siberia. Indeed, humans represent the only primate species other than the Japanese macaque that has adapted to boreal conditions?where temperatures remain far below freezing for more than half the year?pointing to intense selection pressures that likely drove the enhancement of physiological processes that generate and conserve heat. However, despite the fact that humans have lived in cold climates for millennia, we still know very little about how this process of adaptation occurred at the genetic level. The native populations of Siberia provide the best opportunity to investigate the genetic basis of cold resistance given their long-term residence in some of the coldest climates on earth. While much of northern Europe was under ice throughout the last glacial period, Siberia remained relatively ice free, and archaeological evidence suggests that people inhabited this region for more than 40,000 years. The successful long-term settlement of this area by humans undoubtedly required multiple adaptations to deal with the extended severe cold stress, dramatic variation in photoperiod, and limited and highly variable food resources. This project will gather genome-wide polymorphism data from 15 populations that live across a large area of Siberia, from regions of southern Siberia to the northernmost settlements on the Taymyr peninsula within the Arctic Circle. Patterns of variation in these cold-adapted populations will be compared with those from Central and East Asian populations that live in warmer climates. Particular attention will be paid to genomic regions containing genes that have been previously implicated in cold adaptation, or that function in known pathways connected to energy metabolism or cold-adapted traits. The combination of dense genetic data, wide geographic population coverage, and several powerful methods for detecting the signatures of natural selection will offer the most comprehensive picture of genetic adaptation to cold in humans to date.