Viruses in marine food webs

病毒是海洋浮游生物中最丰富的生物制剂，对海洋生物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揭示海洋浮游生物中病毒和宿主多样性之间的关系，以及它如何影响整体速率过程。这些分子技术包括针对细菌宿主的16S rRNA和其他基因的分子指纹图谱，以及针对病毒群落的脉冲场凝胶电泳。该项目将使用这些方法，连同其他技术，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娜岛之间的箭牌时间序列地点（WTSS），以及洛杉矶和卡塔利娜岛附近更丰富的沿海水域。该项目的一部分内容是继续在WTSS现有的4至500米深度的病毒丰度和病毒群落组成的每月时间序列，以增加在其他财政支助下在该地点进行的其他微生物和海洋学观测。除了继续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，我们将使用该采样来测试关于特定常见海洋细菌群的病毒控制的假设，最初针对SAR 11集群，蓝藻和海洋α变形菌。其他重点实验也将针对这些群体。SAR 11和蓝藻是很好的目标，因为(a)它们无处不在，通常各占细菌的5-30%；(b)它们的成员在世界范围内彼此关系非常密切，但与其他已知的群体相距遥远；(c)公布了两个群体的16S rRNA和16S- 23s基因间间隔序列的广泛数据库（以及蓝藻中的其他基因）。(d)两组都是可培养的，SAR11组最近刚在稀释培养中分离出来，有多株菌株报道。短期，更频繁的抽样和实验中观将用于检查群落和特定亚群的动态在生成时间尺度。该项目的附加价值是利用了一个容易到达的海洋地点的独特的微生物多样性时间序列，适合进一步分析这类关于海洋微生物多样性和稳定性的测试假设。样品（如保存的病毒浓缩物、微生物DNA）也可用于回顾性分析。沉积物中病毒多样性和活性的探索性调查也作为一个次要组成部分。这个项目的更广泛影响包括有代表性不足的群体参与的培训和教育部分，加强研究和教育基础设施，以及计划广泛传播研究结果。

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.