Collaborative Research: Seasonal bloom dynamics: Synechococcus-grazer interactions as a model system

合作研究：季节性水华动态：聚球藻-食草动物相互作用作为模型系统

• 批准号: 1233788
• 负责人: Peter Countway
• 金额: $ 75.62万
• 依托单位: Bigelow Laboratory for Ocean Sciences
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-09-01 至 2017-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1233788&HistoricalAwards=false
• 关键词: Collaborative; Research; Seasonal; bloom; dynamics

Cyanobacteria in the genus Synechococcus are minute, but ubiquitous phytoplankton of temperate oceans that contribute a large amount of the biomass produced at the base of marine food webs. Seasonal blooms of Synechococcus are a remarkably consistent feature of coastal water of both the Atlantic and Pacific oceans. However, new molecular techniques have revealed that underlying the consistency of these blooms is a wealth of genetic variation that exhibits rapid dynamical turnover. This has led to a hypothesis that genetic diversity within Synechococcus is ecologically important to sustaining seasonal blooms, and to predicting marine ecosystem response to longer term environmental change. This project will combine ecological and genomic approaches to understand how genetic diversity interacts with the physical and food web processes that drive seasonal cycles of Synechococcus blooms. The genetic diversity of Synechococcus and co-occurring microbes will be quantified on a weekly basis during bloom periods in Booth Bay, Gulf of Maine and Scripps Pier, Southern California. Flow cytometric cell sorting in combination with molecular approaches will be utilized to investigate the diversity of bloom assemblages using a three-tiered approach including: DNA and RNA analysis of the whole unsorted community, DNA analysis of flow-sorted communities, and single cell genomics of Synechococcus and their protist grazers. Ecological processes that cause Synechococcus blooms to end will be investigated through experiments designed to measure the relative importance of mortality from protist grazers versus from viruses on various Synechococcus ecotypes. These results will yield insights into bloom dynamics and how genetic diversity interacts with ecosystem processes.This project will develop methods and resources that will be generally useful for quantifying variability of the seasonal bloom of phytoplankton, which is likely to be an early indicator of ecosystem responses to longer term climate change. Quantitative PCR methods will be designed for rapid quantification of diversity in Synechococcus and in Synechococcus grazers in marine waters. Numerous protist and Synechococcus single amplified genomes will be produced and cryo-preserved to enable future studies. This project will also support the research training of a graduate student and several undergraduate students, who will be intimately involved with individual projects. Results will be translated to formal courses held at Bigelow Laboratory and to the public through presentations at a successful weekly Café Scientifique series held in Boothbay Harbor each summer.

聚球藻属中的蓝细菌是微小的，但在温带海洋中普遍存在的浮游植物，其贡献了海洋食物网底部产生的大量生物质。 季节性的聚球藻水华是大西洋和太平洋沿海水域的一个非常一致的特征。 然而，新的分子技术揭示，这些开花的一致性背后是丰富的遗传变异，表现出快速的动态周转。 这导致了一种假设，即聚球藻属内的遗传多样性对维持季节性水华和预测海洋生态系统对长期环境变化的反应具有重要的生态意义。 该项目将结合联合收割机生态和基因组的方法，以了解遗传多样性如何与物理和食物网的过程，驱动季节性周期的聚球藻开花相互作用。 在缅因州湾布斯湾和南加州斯克里普斯码头的水华期间，将每周对聚球藻属和共生微生物的遗传多样性进行量化。 流式细胞仪细胞分选与分子方法相结合，将被用来调查的多样性，使用三层的方法，包括：DNA和RNA分析的整个未分选的社区，DNA分析的流式分选社区，单细胞基因组聚球藻及其原生动物的草食动物。 生态过程，导致聚球藻水华结束将通过实验进行调查，旨在衡量死亡率的相对重要性，从原生动物食草动物与病毒对各种聚球藻生态型。这些结果将有助于深入了解水华动态以及遗传多样性如何与生态系统过程相互作用。该项目将开发方法和资源，用于量化浮游植物季节性水华的变异性，这可能是生态系统对长期气候变化反应的早期指标。 定量PCR方法将被设计用于快速定量海洋沃茨中聚球藻和食草聚球藻的多样性。 许多原生生物和聚球藻单扩增基因组将产生和冷冻保存，使未来的研究。 该项目还将支持一名研究生和几名本科生的研究培训，他们将密切参与各个项目。研究结果将被转化为毕格罗实验室举办的正式课程，并通过每年夏天在布斯贝港举办的每周一次的成功的科学咖啡馆系列讲座向公众展示。