Copper Metabolism in Marine Synechococcus

微量金属样品的处理和分析发现，微小（纳摩尔）水平的金属，如铁，对海洋中初级生产者的多样性、丰度和碳固定有着深远的影响。这些重要的初级生产者之一，海洋蓝藻，也同样受到铜（自然和人为）水平的积极和消极影响，也可能受到钴和镍水平的影响。与此同时，蓝藻和其他浮游植物正在通过吸收改变金属的分布及其反应性，这导致地表水中金属的可测量损耗，并通过细胞外金属结合配体的产生。由于铜在水生环境中的重要性，pi将利用全基因组测序项目揭示的贫营养环境和沿海环境中具有非常不同金属生理的模型聚球菌菌株来表征海洋蓝藻中的铜代谢。他们将利用全基因组微阵列探测细胞的整体反应，表征菌株对不同铜水平的反应，并将这些研究与细胞内金属水平的最新表征以及细胞生理学和光合能力的其他测量相结合。各种铜相关基因的分子遗传学研究将进行，以确定其在细胞中的功能。初步结果已经发现了一个潜在的候选细胞内铜结合蛋白是保守的所有海洋蓝藻。与此同时，初步结果发现，沿海蓝藻对铜的抵抗力比开放海洋物种更强，这可能是由于一种新的铜结合或外排系统。这些项目将通过开发动手实验组件来说明铜在水生环境中的重要性，这些组件将向中学生传达海洋环境中金属营养/污染的一些基本概念。这项工作将与Aquatic Adventures合作进行，后者提供教育项目，将缺乏服务的青少年与科学联系起来。更广泛的影响这项研究将揭示一些主要的机制，海洋蓝藻已经适应了沿海和贫营养环境中的金属水平。因此，这些结果将有助于我们了解这些生物的分布和多样性与全球初级生产力的关系。它们应该会为沿海环境中的金属应力和污染提供更强大的生物标志物。pi将扩展之前的外展活动，如他们在加州拉霍亚的伯奇水族馆举办的海洋基因组学博物馆展览，通过开发动手实验组件，向中学生传达海洋环境中金属营养/污染的一些基本概念。这项工作将与Aquatic Adventures合作进行，后者提供教育项目，将缺乏服务的年轻人与科学联系起来，激发环保行动，并增加对海洋栖息地的接触。此外，还将培养一名微生物金属生理学跨学科领域的本科生和研究生。

Trace metal sample handling and analysis have led to the discovery that tiny (nanomolar) levels of metals such as iron are having profound influences on the diversity, abundance, and carbon fixation of primary producers in the oceans. One of these important primary producers, marine cyanobacteria, have similarly been shown to be affected, positively and negatively, by copper (natural and anthropogenic) levels and may also be influenced by cobalt and nickel levels. At the same time, cyanobacteria and other phytoplankton are changing the distributions of metals and their reactivity through uptake, which causes measurable depletion of metals in surface waters, and through the extra-cellular production of metal binding ligands. Because of the importance of copper in aquatic environments, the PIs will characterize copper metabolism in marine cyanobacteria using model Synechococcus strains from oligotrophic environments and from coastal environments that have very different metal physiologies revealed by the whole genome sequencing projects. They will characterize how the strains respond to different copper levels using whole genome microarrays that probe the global response of the cell and will combine these studies with state of the art characterization of intracellular metal levels and other measures of cellular physiology and photosynthetic capacity. Molecular genetics studies of diverse copper associated genes will be undertaken to determine their function in the cell. Preliminary results have found a potential candidate for an intracellular copper binding protein that is conserved in all marine cyanobacteria. At the same time, preliminary results have found that coastal cyanobacteria have greater resistance to copper than open ocean species and this might be due to a novel copper binding or efflux system. The PIs will illustrate the importance of copper in aquatic environments by developing hands-on lab components that will communicate some basic concepts around metal nutrition/pollution in the marine environment to middle school students. This will be undertaken in collaboration with Aquatic Adventures, who provide educational programs that connect underserved youth to science.Broader Impacts This research will reveal some of the major mechanisms by which marine cyanobacteria have adapted to metal levels in coastal and oligotrophic environments. Thus these results will help us understand the distribution and diversity of these organisms in relation to global primary productivity. They should lead to more robust biomarkers for metal stress and pollution in coastal environments. The PIs will expand on a previous outreach activity like their museum exhibit on marine genomics at the Birch Aquarium, La Jolla CA, by developing hands-on lab components that will communicate some basic concepts around metal nutrition/pollution in the marine environment to middle school students. This will be undertaken in collaboration with Aquatic Adventures, who provide educational programs that connect underserved youth to science, inspire environmental action, and increase exposure to marine habitats. In addition an undergraduate and graduate student in the interdisciplinary field of the metal physiology of microbes will be trained.