Copper Metabolism in Marine Synechococcus

痕量金属样品处理和分析发现，铁等微量（纳摩尔）金属对海洋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，海洋蓝细菌，同样被证明是积极和消极的影响，铜（自然和人为）的水平，也可能受到钴和镍的水平。与此同时，蓝细菌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，这导致表层沃茨中金属的可测量的消耗，并通过金属结合配体的细胞外生产。由于铜在水生环境中的重要性，PI将使用来自贫营养环境和沿海环境的聚球藻模型菌株来表征海洋蓝藻中的铜代谢，所述聚球藻具有由全基因组测序项目揭示的非常不同的金属生理学。他们将使用全基因组微阵列来表征菌株对不同铜水平的反应，该微阵列探测细胞的全局反应，并将联合收割机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。将对不同的铜相关基因进行分子遗传学研究，以确定它们在细胞中的功能。初步结果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，初步研究结果发现，沿海蓝藻对铜的抵抗力比公海物种更强，这可能是由于一种新的铜结合或外排系统。PI将通过开发动手实验室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。这项研究将与Aquatic Adventures合作进行，后者提供教育项目，将服务不足的青年与科学联系起来。更广泛的影响这项研究将揭示海洋蓝藻适应沿海和贫营养环境中金属水平的一些主要机制。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。他们应该导致更强大的生物标志物的金属压力和污染在沿海环境。PI将扩大以前的外展活动，如他们在加州拉霍亚的桦树水族馆举办的海洋基因组学博物馆展览，通过开发动手实验室组件，将围绕海洋环境中的金属营养/污染向中学生传达一些基本概念。这将与Aquatic Adventures合作进行，后者提供教育计划，将服务不足的青年与科学联系起来，激励环保行动，并增加对海洋栖息地的接触。此外，还将培训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.