RAPID: El Nino and the controls of marine virus diversity

2009年7月，NOAA国家气象局气候预测中心宣布厄尔尼诺的到来，这是赤道太平洋海面温度（SST）异常变暖的一个事件，每3-8年发生一次。该项目将调查厄尔尼诺现象对海洋病毒群落的影响，使用感染蓝细菌Synecompycocus的噬藻体作为模型系统。即将到来的厄尔尼诺现象为进一步研究噬藻体多样性的时间变异性提供了一个机会，该项目的目标是：（1）解开影响噬藻体多样性的各种非生物因素，（2）通过比较噬藻体适应温度和宿主组成的进化过程，测试噬藻体多样性时间变异性背后的机制。为了实现这些目标，每月从南加州湾的三个沿海地点分离约150只噬藻体。纯化的分离株将通过对其g20基因进行测序来表征。将对这些分离株和以前非厄尔尼诺年的分离株进行表型分析，厄尔尼诺所造成的环境变异对本项目的两个部分都至关重要。这将有助于解开共变因子对原位噬藻体组成的影响。例如，在南加州，厄尔尼诺现象在紫外线强度相对较低的月份（秋季和冬季）应提供高于正常的SST。它还将允许从更广泛的环境条件中分离出更广泛的噬藻体遗传多样性，为实验室实验提供关键的统计能力。该项目将加深我们对海洋病毒多样性控制机制的理解，更广泛的影响包括加深对病毒多样性如何在海洋中分布和维持的理解。海洋微生物的病毒裂解改变了溶解有机物和无机营养物的库，因此可能对海洋生物地球化学循环产生重大影响。该项目也将是第一个调查厄尔尼诺现象对任何非致病性病毒群落的影响的项目。此外，它将有助于培训至少3名本科生和一名博士生。

AbstractIn July 2009, the NOAA National Weather Service Climate Prediction Center announced the arrival of El Niño, an episode of abnormal warming of sea surface temperature (SST) in the equatorial Pacific that occurs every 3-8 years. This project will investigate the impact of El Niño on marine virus communities, using cyanophages that infect the cyanobacterium Synechoccocus as a model system. The upcoming El Niño presents an opportunity to advance research on the fundamental question of what drives temporal variability in cyanophage diversity.The goals of this project are: (1) to disentangle various abiotic factors that influence cyanophage diversity and (2) to test the mechanisms behind temporal variability in cyanophage diversity, by comparing the evolutionary processes by which cyanophages adapt to temperature and host composition. To meet these objectives, ~150 cyanophage will be isolated monthly from three coastal sites in the Southern California Bight. The purified isolates will be characterized by sequencing their g20 gene. Phenotypic assays will be carried out on a selection of these isolates and isolates from the previous non-El Niño years.The environmental variability that El Niño will provide is crucial to both parts of this project. It will help to disentangle the effect of covarying factors on in situ cyanophage composition. For instance, in Southern California, El Niño should provide higher-than-normal SST during months of relatively low UV intensity (fall and winter). It will also permit isolation of a broader genetic diversity of cyanophages from a wider array of environmental conditions, providing crucial statistical power to the laboratory experiments. The project will further our mechanistic understanding of the controls of marine virus diversity.Broader impacts consist of an increased understanding of how virus diversity is distributed and maintained in the ocean. Viral lysis of marine microorganisms alters the pools of dissolved organic matter and inorganic nutrients and therefore may have a major impact on marine biogeochemical cycling. The project will also be the first to investigate the impact of El Niño on any non-pathogenic virus community. Further, it will contribute to the training of at least 3 undergraduate students and a PhD student.