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: 1233085
• 负责人: Brian Palenik
• 金额: $ 31.79万
• 依托单位: University of California-San Diego Scripps Inst of Oceanography
• 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=1233085&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.

聚球藻属中的蓝藻虽然微小，但却是温带海洋中普遍存在的浮游植物，为海洋食物网基础产生的大量生物量提供了贡献。 聚球藻的季节性繁殖是大西洋和太平洋沿岸水域的一个非常一致的特征。 然而，新的分子技术表明，这些花朵的一致性背后隐藏着大量的遗传变异，这些变异表现出快速的动态更新。 这导致了一种假设，即聚球藻内的遗传多样性对于维持季节性开花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。 该项目将结合生态学和基因组方法，以了解遗传多样性如何与驱动聚球藻开花季节性周期的物理和食物网过程相互作用。 在缅因湾布斯湾和南加州斯克里普斯码头的花期期间，将每周对聚球藻和共生微生物的遗传多样性进行量化。 流式细胞术细胞分选与分子方法相结合，将用于研究水华组合的多样性，采用三层方法，包括：整个未分选群落的 DNA 和 RNA 分析、流式分选群落的 DNA 分析以及聚球藻及其原生食草动物的单细胞基因组学。 将通过旨在测量原生食草动物死亡率与各种聚球藻生态型病毒死亡率的相对重要性的实验来研究导致聚球藻繁殖结束的生态过程。这些结果将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。该项目将开发通常可用于量化浮游植物季节性水华变化的方法和资源，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水中聚球藻和食草聚球藻的多样性。 将生产并冷冻保存大量原生生物和聚球藻单一扩增基因组，以方便未来的研究。 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成功的每周一次的科学咖啡馆系列演讲向公众展示。