En-Gen: Proteomics Directed Environmental Genomics: Identifying in Situ Physiological Diversity of Cyanobacterial Nutrient Utilization in the South Atlantic Ocean

单细胞海洋蓝藻、原氯球菌和聚球藻占世界中纬度初级生产力的50%-S海洋。这些蓝藻的系统发育、生理学和生物地理表明，它们由几个密切相关的生态型组成。这些光适应的谱系和亚系在垂直和纬度分布上不同，尽管驱动它们分布的生理适应还没有被很好地理解。对原氯球菌和聚球藻的比较基因组研究表明，营养吸收和胁迫反应基因的横向转移可能推动了海洋环境中的遗传微多样性和生态位分配。因为蛋白质，而不是基因，在特定的条件下决定了生物体的表型，蛋白质组学方法是微生物过程现场验证的理想方法。该项目建议应用南大西洋光区的蛋白质组和基因组调查来探索营养和应激反应基因在塑造海洋蓝藻群落结构中的作用。除了确定不同基因家族中活跃表达的基因外，该项目的结果还将有助于澄清营养动态和浮游细菌群落结构之间的关系。此外，海洋蓝藻为使用环境基因组和蛋白质组方法研究驱动生态位分化的机制提供了一个模型系统。该项目还将让海洋科学领域的年轻研究人员参与进来，让他们做好利用基因组方法的准备。一名博士后助理和几名本科生也将积极参与研究计划。该项目的数据将用于为在华盛顿大学教授的环境基因组学研究生课程开发一个计算机实验室模块，这一提议的支持还将使百慕大海洋科学研究所夏季微生物海洋学课程中的蛋白质组学部分得以扩展。

The unicellular marine cyanobacteria Prochlorococcus and Synechococcus account for up to 50% of primary productivity at mid latitudes in the world?s oceans. The phylogeny, physiology, and biogeography of these cyanobacteria suggest that they are comprised of several closely related ecotypes. These light adapted lineages and sublineages differ in vertical and latitudinal distributions, although the physiological adaptations that drive their distributions are not yet well understood. Comparative genomic studies of both Prochlorococcus and Synechococcus suggest that the lateral transfer of nutrient uptake and stress response genes may be driving genetic microdiversity and niche partitioning in the marine environment. Because proteins, rather than genes, determine an organism's phenotype under a defined set of conditions, proteomic approaches are ideal for in situ verification of microbial processes. This project proposes to apply a proteomic and genomic survey of the South Atlantic photic zone to explore the role of nutrient and stress response genes in shaping community structure of marine cyanobacteria. In addition to identifying actively expressed genes within diverse gene families, results from this project will help clarify relationships between nutrient dynamics and bacterioplankton community structure. Further, marine cyanobacteria provide a model system for using environmental genomic and proteomic approaches to investigate mechanisms driving niche differentiation. The project will also involve young investigators in the ocean sciences by preparing them to take advantage of genomic approaches. A post-doctoral associate and several undergraduate students will also be actively involved in the research program. Data from this project will be used to develop a computer laboratory module for a graduate course in environmental genomics taught at the University of Washington, and support from this proposal will also allow expansion of a proteomics component in the summer Microbial Oceanography course at the Bermuda Institute for Ocean Science.