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

单细胞海洋蓝藻原绿球藻和聚藻球菌占世界中纬度地区初级生产力的50%。年代的海洋。这些蓝藻的系统发育、生理学和生物地理学表明它们是由几个密切相关的生态型组成的。这些适应光的谱系和亚谱系在垂直和纬度分布上有所不同，尽管驱动它们分布的生理适应尚未得到很好的理解。原绿球藻和聚球藻的基因组比较研究表明，营养吸收和应激反应基因的横向转移可能是海洋环境中遗传微多样性和生态位分配的驱动因素。因为蛋白质，而不是基因，在一定条件下决定生物体的表型，蛋白质组学方法是微生物过程原位验证的理想方法。本项目拟对南大西洋光区进行蛋白质组学和基因组学调查，探讨营养和应激反应基因在海洋蓝藻群落结构形成中的作用。除了确定不同基因家族中活跃表达的基因外，该项目的结果将有助于阐明营养动态与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学和蛋白质组学方法研究驱动生态位分化的机制提供了一个模型系统。该项目还将涉及海洋科学领域的年轻研究人员，为他们利用基因组方法做好准备。一名博士后和几名本科生也将积极参与研究项目。该项目的数据将用于开发华盛顿大学环境基因组学研究生课程的计算机实验室模块，该提案的支持还将允许在百慕大海洋科学研究所的夏季微生物海洋学课程中扩展蛋白质组学部分。

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.