Collaborative Research: A millennial-scale chronicle of organism-environment interactions resulting in microevolutionary physiological and genomic shifts in Daphnia

当代生物学面临的一个核心挑战是了解生物体如何适应不断变化的环境。这项研究的重点是动物种群生理学的微观进化变化的预测是否可以基于生态系统水平的信息。这些问题的答案应该有助于建立更好的全球环境变化预测模型，并为有效管理提供信息。利用一种独特的模式生物水蚤，一种生活在湖泊中的小型甲壳类动物，它产生的卵可以在沉积物中休眠几个世纪，首席调查员（pi）已经能够直接观察到人为变化对自然种群的进化后果。在这个项目中，pi将阐明观察到的进化变化背后的确切机制，这些变化与关键环境参数(如磷(P)装载历史（即影响水质的营养富集）的变化相一致。具体来说，他们将使用最先进的古湖泊学工具来检查湖底沉积物，以精确地重建反映欧洲人之前和之后定居的过去环境，并利用这些信息来测试古代和现存水蚤基因型的表现，以评估人为影响。此外，他们将结合实验进化和高通量基因组学方法来识别这种进化转变背后的基因。还将评估这些基因在预测不同湖泊对营养富集（即富营养化）的反应方面的表现。私立学校将继续从不同层次（高中、本科和研究生）代表性不足的群体中招收学生。本项目将培养1名博士后、3名研究生、1名博物馆实习生、3名本科生研究助理和1名高中实习生。从拟议的实验中产生的基因组信息将尽快通过www.wFleabase.org提供给科学界，而在此项目中产生的水蚤克隆库将在资助期限后共享。此外，这项研究的结果与水质和环境变化问题有关（特别是来自古湖泊学分析的结果），pi将继续与明尼苏达州自然资源部分享数据，以便向湖泊管理者和公众推广。与明尼苏达科学博物馆合作，该项目将成为美国国家科学基金会（nsf）赞助的屡获殊荣的www.sciencebuzz.org在线展览的一部分，该展览将最新的科学新闻（通过RSS技术）与传统的博物馆互动体验相结合，每年可能吸引50万至80万人。pi将提供有关全球环境变化的内容，特别是与湖泊有关的内容，以及水生生物适应变化条件的能力。最后，这项工作得益于联邦资助的资源，如水蚤基因组学联盟和国家湖泊核心设施。

A central challenge facing contemporary biology is to understand how organisms adapt to changing environments. This research focuses on whether predictions of microevolutionary shifts in the physiology of animal populations can be based on ecosystem-level information. Answers to such questions should foster better forecasting models of global environmental change and inform effective management. Using a unique model organism, Daphnia, a small crustacean that lives in lakes and produces resting eggs that can lay dormant in sediments for centuries, the Principal Investigators (PIs) have been able to directly observe the evolutionary consequences of man-made change in a natural population. In this project, the PIs will elucidate the precise mechanisms that underlie observed evolutionary shifts coinciding with changes in key environmental parameters such as phosphorus (P) loading history (i.e., nutrient enrichment that affects water quality). Specifically, they will use cutting-edge paleolimnological tools to examine lake-bottom sediments to precisely reconstruct erstwhile environments reflective of pre- and post-European settlement, and use that information to test the performance of ancient and extant Daphnia genotypes to assess anthropogenic impacts. Furthermore, they will couple experimental evolution, and high throughput genomics methods to identify the genes that underlie such evolutionary shifts. The performance of these genes in predicting responses to nutrient enrichment (i.e., eutrophication) in a different lake will also be assessed. The PIs will continue to recruit students from underrepresented groups at various levels (high-school, undergraduate, and graduate). This project will train a postdoctoral fellow, three graduate research students, a museum intern, three undergraduate research assistants, and a high school intern. The genomic information generated from the proposed experiments will be made available to the scientific community via www.wFleabase.org as soon as possible, while the Daphnia clone bank generated during this project will be shared after the duration of the grant. Moreover, results from this study are relevant to issues of water quality and environmental change (particularly from paleolimnological assays), and the PIs will continue to share data with the Minnesota Department of Natural Resources for outreach to lake managers and the general public. In partnership with the Science Museum of Minnesota, the project will be part of the NSF-sponsored award-winning www.sciencebuzz.org online exhibits that blend up-to-the-minute science news (via RSS technology) with traditional museum interactive experiences, reaching potentially 500,000-800,000 individuals per year. The PIs will provide content on global environmental change, particularly related to lakes, and the ability of aquatic organisms to adapt to changing conditions. Finally, this work contributes to and benefits from federally-funded resources such as the Daphnia Genomics Consortium and the National Lacustrine Core Facility.