RoL: Leveraging wild yeast to identify genetic mechanisms of climate adaptation in natural populations

自然种群能否适应气候变化？在一个迅速变化的世界中，迫切需要了解适应所需的条件。在过去，不相关的种群或物种以相似的方式独立适应温度升高。本研究的目的是利用这种自然实验重复来确定适应的生态、生理和遗传预测因素。对于动物或植物来说，从技术上很难发现编码新性状的精确遗传机制。这项研究的重点是许多野生酵母种群，包括遗传学的模式生物，酿酒酵母，人类也用它来发酵食物和饮料。酵母菌在实验室中是非常容易处理的，甚至在野生森林中也有驯化的酵母菌种群，它们的种群生物学与动物的种群生物学惊人地相似。该项目的工作将通过综合现场、实验室和生物信息学方法，提供高需求的跨学科培训。它将培训本科生和研究生，包括来自科学领域代表性不足群体的学生。研究人员还将测试天然酵母热适应的相同原理是否也支配着野生酵母对当地人类相关环境的适应。家庭、小学生和社区中的其他人将通过当地活动和学校访问了解研究的概念和结果。趋同进化的种群为理解适应的生态、表型和分子基础提供了自然复制。研究小组的总体目标是利用酵母的热适应作为研究系统，确定野生趋同进化的突变和进化过程。该研究将通过从包括酿酒酵母在内的四种林地物种中取样许多酵母种群，来测试物种内和跨系统发育尺度的趋同热进化。群体基因组分析将区分新的适应性突变与现有的遗传变异或基因流动。野生酵母遗传学的力量可以显示出适应的潜在机制，其程度在任何其他系统中几乎是不可能的。实验包括分析，以推断系统发育关系，以检测收敛和进化背景；野外取样和生理筛选鉴定天然酵母群体的热适应性；趋同性热适应突变的鉴定及其转基因等位基因交换验证通过建立包括突变可利用性、表型可塑性、种群大小和生长在内的相关机制模型，对物种范围和气候变化响应进行综合分析。该基金由生物科学理事会综合生物系统部门的综合生态生理学项目、环境生物学部门的进化过程集群和新兴前沿部门的生命规则共同资助。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Will natural populations adapt in the face of climate change? In a rapidly changing world, there is an urgent need to know the conditions necessary for adaptation. In the past, unrelated populations or species independently adapted in similar ways to increased temperatures. The goal of this research is to use such natural experimental replicates to identify ecological, physiological and genetic predictors of adaptation. For animals or plants, it is technically difficult to discover the precise genetic mechanism encoding new traits. This research focuses instead on many wild populations of yeast and includes the model organism for genetics, Saccharomyces cerevisiae, which humans also use to ferment food and beverages. Yeast are exceptionally tractable in the laboratory, and there are wild forest populations of even domesticated species with population biology that is surprisingly similar to that of animals. Work on this project will provide an interdisciplinary training that is in high demand by integrating field, laboratory and bioinformatic approaches. It will train undergraduate and graduate students, including students from underrepresented groups in science. Researchers will also test whether the same principles of natural yeast thermal adaptation also governed adaptation of wild yeast to local human-associated environments. Families, elementary school children and others in the community will learn about the concepts and findings of the research through local events and school visits.Populations that show convergent evolution provide natural replicates for understanding the ecological, phenotypic and molecular basis of adaptation. The research team's overall objective is to identify the mutations and evolutionary processes that characterize convergent evolution in the wild, using thermal adaptation in yeast as the study system. The research will test for convergent thermal evolution within species and across phylogenetic scales by sampling many yeast populations from four woodland species, including Saccharomyces cerevisiae. Population genomic analyses will distinguish new adaptive mutations from standing genetic variation or gene flow. The power of wild yeast genetics can show the underlying mechanisms of adaptation to an extent that would be almost impossible in any other system. The experiments involve analyses to infer phylogenetic relationships for detecting convergence and evolutionary context; field sampling and physiological screens identifying thermal adaptation in natural yeast populations; the identification of mutations underlying convergent thermal adaptation, their verification using transgenic allele swaps; and integrated analyses predicting species ranges and climate change response by generating correlative and mechanistic models that include mutation availability, phenotypic plasticity, population size and growth.This grant was cofunded by the Integrative Ecological Physiology Program in the Division of Integrative Organismal Systems, the Evolutionary Processes Cluster in the Division of Environmental Biology, and The Rules of Life in the Division of Emerging Frontiers in Directorate for Biological Science.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.