Viruses in marine food webs

病毒是海洋浮游生物中最丰富的生物因子，对海洋生物过程，包括物质能量流动以及浮游生物多样性具有巨大的潜在影响。研究宿主细菌和病毒多样性的新分子方法使研究人员开始解开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。这些分子技术包括细菌宿主的16 S 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。该项目将利用这些方法，沿着其他技术，研究自然和实验性海洋微生物系统，并探讨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纳岛附近较丰富的沿海沃茨。该项目的一部分是继续在WTSS对4个深度至500米的病毒丰度和病毒群落组成进行现有的每月时间序列，以增加在该地点进行的其他微生物学和海洋学观测，并提供其他财政支助。除了一般的时间序列数据库组件，继续提供有价值的微生物群落数据在其本身的权利，我们将使用这种采样来测试假设病毒控制特定的常见群体的海洋细菌，最初针对SAR 11集群，蓝藻，和海洋α蛋白菌。其他重点实验也将针对这些群体。SAR 11和蓝细菌是良好的靶，因为（a）它们普遍存在，并且通常各自占细菌的5-30%（B）它们的成员在世界范围内彼此非常密切相关，但与其他已知的组相距甚远（c）公开了两个组的16 S rRNA和16 S-23 S基因间间隔区序列的广泛数据库（以及蓝细菌中的其他基因），便于在高分辨率下研究菌株组成，而无需培养生物体。（d）两组都是可培养的，SAR 11组最近刚刚在稀释培养物中分离，报告了多种菌株。 将采用短期、更频繁的取样和实验性围隔生态系统来研究世代时间尺度上的群落和特定亚群动态。该项目的附加值是利用一个容易进入的海洋地点的微生物多样性的独特时间序列，适合于进一步分析这种与海洋微生物的多样性和稳定性有关的假设。还将提供样本（例如，保存的病毒浓缩物、微生物DNA）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次要组成部分包括在内。这一项目的更广泛影响包括由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，并计划广泛传播成果。

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.