Physiology and Genomic architecture of fine-scale adaptation

传统上，对基因如何影响对环境压力的抵抗力的理解是基于这样的假设，即少数几个罕见的基因有很大的影响。另一种想法是，在许多个体中存在许多不同的基因，但每个基因都有很小的影响。将许多影响较小的基因相加，最终会产生较大的反应。这一新想法改变了对个体变异及其对人类健康的影响的研究，以及对动植物未来成功的预测。这项研究通过比较暴露在不同环境压力下的不同人群来检验这些想法。利用这些种群，研究小组将确定这些种群之间的遗传差异，并将这些遗传差异与生理测量联系起来。根据这些数据，研究小组将确定影响对环境反应的基因数量，并预测个人如何应对环境压力。据预测，有大量的基因可以改变个体对环境压力的反应。如果是正确的，这表明有许多不同的基因组合可以很好地对环境做出反应。这样的结果将有助于解决一个悬而未决的问题，即为什么自然界中的遗传多样性如此丰富？此外，了解健康个体之间的自然变异将为物种如何应对不断变化的世界提供更准确的预测。最后，除了研究成果，该项目还将增加当地社区大学生的教育机会，并培训综合生物生物学的研究生。适应压力环境是如何发挥作用的，它是依赖于新的突变还是长期的遗传变异，涉及多个小效应基因，还是主要是由于几个大效应基因？更好地理解适应环境的本质将为环境变化如何影响物种生存提供更准确的预测。对于生态和生理过程，经典的假设一直是适应涉及一个或几个基因，但似乎许多基因影响健康或影响生物体成功的生物过程。尽管有很多争论，但我们对适应性变异理解的一个潜在的重大转变表明，涉及多个座位的多基因软扫描导致了选择性优势。如果许多个体在祖先群体中携带替代的等位基因，那么涉及多个基因座的适应是可能的。由于许多可供选择的等位基因频率相对较高，适应速度更快，成本更低。这里提出的研究将提供必要的经验数据来解决多基因软扫描的频率问题。此外，这项研究还将为预测和量化适应性差异提供数据。这项研究将专门研究占据不同微生境的硬骨鱼Fundulus heroclatus高通量序列的时间变化，并将这些变化与生理过程(CTmax、低氧-CTmax和心脏代谢)的测量相结合。研究小组将跟踪占据不同微生境的队列。这些数据解决了两个目标：1)确定微生境中显著的等位基因频率差异是否是由于单个季节中个体的选择性丧失，以及2)检查等位基因频率改变的生理后果。该奖项由生物科学局内的综合组织系统司、环境生物学司和生命规则风险基金共同资助。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Classically, the understanding of how genes influence resistance to environmental stress was based on the assumption that a few rare genes have large effects. An alternate idea is that there are many different genes that occur in many individuals, but each gene has a small effect. Adding up many genes of small effect ultimately results in a large response. This new idea changes the study of individual variation, its effects on human health, and the prediction about the future success of animals and plants. This research tests these ideas by comparing different populations exposed to different environmental stressors. Using these populations, the research team will determine the genetic differences among these populations and connect these genetic differences to physiological measurements. From these data, the team will determine the number of genes that influence the response to the environment and predict how individuals respond to environmental stress. The prediction is that there are a large number of genes that can alter an individual's response to environmental stress. If correct, this suggests that there are many different combinations of genes that work well to respond to the environment. Such a result would help resolve an unsolved question, why is genetic diversity so abundant in nature? Additionally, understanding, natural variation among healthy individuals will provide more accurate forecasts of how species will respond to a changing world. Finally, in addition to the research outcomes, the project will enhance educational opportunities for local community college students and train of graduate students in integrative organismal biology.How does adaption to stressful environments work, does it depend on new mutations or standing genetic variation, involve many loci of small effect or is it primarily due to a few genes of large effect? A better understanding of the nature of adaptation to the environment will provide more accurate predictions of how changing environments will affect species survival. For ecological and physiological processes, the classic hypothesis has been that adaptation involves one or a few genes, yet it seems likely that many genes affect fitness or biological processes that affect organisms' success. Although there is much debate, a potential major shift in our understanding of adaptive variation suggests that polygenic soft-sweeps involving many loci cause a selective advantage. Adaptation involving many loci is possible if many individuals carry alternative alleles in the ancestral population. With many alternative alleles at relatively high frequencies, adaptation is faster and less costly. The research proposed here will provide the necessary empirical data to address the frequency of polygenic soft-sweeps. In addition, the research will provide data to predict and quantify adaptive divergence. This research will specifically examine the temporal variation in high-throughput sequences among teleost fish Fundulus heteroclitus occupying different microhabitats and combines these with measures of physiological processes (CTmax, hypoxic-CTmax and cardiac metabolism). The research team will follow cohorts through time that occupy different microhabitats. These data address two goals: 1) determine if significant allele frequency differences across microhabitats are due to the selective loss of individuals over a single season, and 2) examine physiological consequences of altered allele frequencies. This award was co-funded by the Division of Integrative Organismal Systems, the Division of Environmental Biology, and the Rules of Life Venture Fund within The Directorate for Biological Sciences.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.