AToL: Collaborative Research: Reconstructing Eukaryotic Phylogeny through Multigene Analyses of Microbial Eukaryotes

要真正了解地球上的生物多样性，需要将微生物正确地放置在生命之树上。 地球上的生命有两种形式：（1）原核生物（细菌和酵母），它们都是微生物，（2）真核生物，有核细胞。 真核生物本身在进化出更熟悉的宏观真核生物群（植物、动物和真菌）之前的大约10亿年里都是微生物。微生物真核生物或原生生物的特征是具有巨大的细胞多样性，并在生态系统中发挥重要作用（例如海洋系统中的碳固定）。 此外，一些微生物真核生物是影响许多国家社会和经济命运的流行传染病（如疟疾）的病原体。 这个合作项目是NSF资助的“组装生命之树”项目的一部分，将通过分析来自200种主要自由生活的原生生物的9个基因的DNA序列来阐明真核生物之间的关系。 对所得数据的分析将把联合收割机现有的系统发育方法与为本项目开发的方法结合起来。 这些分析是必不可少的：1）统一包括原核生物和真核生物的通用生命树，2）理解多细胞真核生物的多种起源，3）解释致病原生生物的起源。这项研究将振兴美国的原生生物研究，同时回答有关真核生命之树的基本问题。至少有三名博士后研究员和三名研究生将被纳入拟议的研究。本科生也将接受研究各方面的培训，主要研究人员将继续致力于从传统上代表性不足的群体中招募学生。 该项目还包括举办一个关于原生生物收集和鉴定（通过光学显微镜）的讲习班。 最后，micro*scope，一个基于网络的探索真核生物多样性的工具（http：//www.mbl.edu/microscope）将扩大到包括多层次的教育材料。

To truly understand biological diversity on Earth requires that microorganisms be correctly placed on the tree of life. Life on Earth exists in two forms: (1) prokaryotes (Bacteria and Archaea), all of which are microbial, and (2) eukaryotes, cells with nuclei. Eukaryotes themselves were exclusively microbial for about one billion years before the evolution of the more familiar macroscopic eukaryotic groups: plants, animals, and fungi. Microbial eukaryotes, or protists, are characterized by tremendous cellular diversity and play an essential role in ecosystems (e.g. carbon fixation in marine systems). Moreover, some microbial eukaryotes are the causative agents of prevalent infectious diseases (e.g. malaria) that impact the social and economic fortunes of many countries. This collaborative project, part of the NSF-funded effort "Assembling the Tree of Life" will elucidate relationships among eukaryotes by analyzing DNA sequences of nine genes from 200 species of predominantly free-living protists. Analyses of the resulting data will combine existing phylogenetic approaches with those developed for this project. These analyses are essential for: 1) unifying the universal tree of life that includes both prokaryotes and eukaryotes, 2) understanding the multiple origins of multicellular eukaryotes, and 3) interpreting the origins of disease-causing protists. The study will invigorate protist research in the U.S. while answering fundamental questions about the eukaryotic Tree of Life. At least three postdoctoral fellows and three graduate students will be integrated into the proposed research. Undergraduates will also be trained in all aspects of the research, and the principal investigators will maintain their commitment to recruiting students from traditionally underrepresented groups. The project also includes the development of a workshop on collection and identification (by light microscopy) of protists. Finally, micro*scope, a web-based tool for exploring eukaryotic diversity (http://www.mbl.edu/microscope) will be expanded to include educational materials at multiple levels.