Viruses in marine food webs

海洋食物网中的病毒

• 批准号: 0241723
• 负责人: Jed Fuhrman
• 金额: $ 40.21万
• 依托单位: University of Southern California
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-02-15 至 2007-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0241723&HistoricalAwards=false
• 关键词: Viruses; marine; food; webs

Viruses are the most abundant biological agents in marine plankton and have a tremendous potential impact on biological oceanographic processes, including material & energy flow as well as plankton diversity. New molecular methods to investigate diversity of host bacteria and viruses permit researchers to begin unraveling the relationships between virus and host diversity in marine plankton, and how it may affect overall rate processes. These molecular techniques include molecular fingerprinting of 16S rRNA and other genes for bacterial hosts, and pulsed field gel electrophoresis for virus communities. This project will use such approaches, along with other techniques, to study natural and experimental marine microbial systems and address basic hypotheses on the relationships between bacterial and viral communities. Study sites will include the Wrigley Time Series Site (WTSS) midway between Los Angeles and Catalina Island, and also richer coastal waters near Los Angeles and Catalina Island. Part of the project is continuation of an existing monthly time series at WTSS of virus abundance and virus community composition at 4 depths to 500 m, to augment other microbiological and oceanographic observations being made at that location with other financial support. In addition to the general time series databasing component which continues to provide valuable microbial community data in its own right, we will use this sampling to test hypotheses about viral control of specific common groups of marine bacteria, initially targeting the SAR 11 cluster, cyanobacteria, and marine alpha proteobacteria. Other focused experiments will also target these groups. SAR 11 and cyanobacteria are good targets because (a) they are ubiquitous and typically each makes up 5-30% of the bacteria (b) their members are very closely related to each other worldwide, yet distant from other known groups (c) an extensive database of 16S rRNA and 16S-23S intergenic spacer sequences for both groups is published (and also other genes in cyanobacteria), facilitating investigation of strain composition at high resolution without the need to culture the organisms (d) both groups are culturable, with the SAR11 group just recently isolated in dilution culture, with multiple strains reported. Short-term, more frequent sampling and experimental mesocosms will be used to examine community and specific subgroup dynamics on the generation time scale. The project has the added value of taking advantage of a unique time series of microbial diversity at an easily accessible marine site, suitable for further analysis such testing hypotheses relating diversity and stability in marine microbes. Samples (e.g. preserved virus concentrates, microbial DNA) will also be available for retrospective analysis. Exploratory investigation of virus diversity and activity in sediments is also included as a minor component. Broader impacts of this project include a training and education component with participation of underrepresented groups, enhancement of the research and education infrastructure, and planned broad dissemination of the results.

病毒是海洋浮游生物中含量最丰富的生物因子，对生物海洋学过程具有巨大的潜在影响，包括物质和能量流动以及浮游生物多样性。研究宿主细菌和病毒多样性的新分子方法使研究人员能够开始解开病毒和海洋浮游生物宿主多样性之间的关系，以及它可能如何影响总体速率过程。这些分子技术包括细菌宿主的16S rRNA和其他基因的分子指纹，以及病毒群落的脉冲场凝胶电泳。该项目将使用这种方法以及其他技术来研究自然和实验海洋微生物系统，并解决关于细菌和病毒群落之间关系的基本假设。研究地点将包括洛杉矶和卡塔利纳岛之间的箭牌时间序列站点(WTSS)，以及洛杉矶和卡塔琳娜岛附近更丰富的沿海水域。该项目的一部分是继续在WTSS现有的4至500米深度的病毒丰度和病毒群落组成的月度时间序列，以加强在该地点进行的其他微生物和海洋学观测，并提供其他财政支助。除了继续本身提供有价值的微生物群落数据的一般时间序列数据库组件外，我们还将使用这次采样来测试关于特定常见海洋细菌组的病毒控制的假设，最初针对的是SAR 11集群、蓝藻和海洋α蛋白细菌。其他有针对性的实验也将针对这些群体。SAR 11和蓝藻是很好的靶标，因为(A)它们无处不在，通常每个细菌占细菌总数的5-30%(B)它们的成员在世界范围内彼此关系非常密切，但与其他已知群的距离很远(C)已公布了两个群的16S rRNA和16S-23S基因间隔区序列的广泛数据库(以及蓝藻中的其他基因)，从而促进了对菌株组成的高分辨率研究，而不需要对生物进行培养(D)两群都是可培养的，SAR11群最近才在稀释培养中分离出来，据报道有多个菌株。短期、更频繁的采样和实验中观将被用来研究世代时间尺度上的群落和特定亚群的动态。该项目的附加价值在于，可以利用易于进入的海洋地点微生物多样性的独特时间序列，适合进一步分析与海洋微生物多样性和稳定性有关的测试假说。样本(如保存的病毒浓缩物、微生物DNA)也将可供追溯分析。还包括对沉积物中病毒多样性和活性的探索性调查，作为次要组成部分。该项目的更广泛影响包括培训和教育部分，代表人数不足的群体参与，加强研究和教育基础设施，以及有计划地广泛传播成果。