Collaborative proposal: Cyanophage-Synechococcus interactions in complex communities

病毒引起的海洋微生物死亡改变了海洋中溶解有机物池的数量和质量，将有机物送回微生物圈，远离更大的海洋食物网。了解病毒在生物地球化学循环中的作用的一个主要障碍是，我们对海洋环境中哪些病毒感染哪些细菌知之甚少。在这个项目中，一个基于网络的框架将用于研究海洋噬菌体-细菌在复杂的多物种群落中的相互作用。这项研究的重点是噬藻病毒，一种感染聚藻球菌的病毒，这是海洋中一种重要的生态蓝藻。这个项目有三个部分。第一部分将通过实验室进化实验和基因组测序来鉴定噬藻-聚囊球菌相互作用的遗传特征。第二部分将通过比较多年前收集的数百个分离株的全基因组序列，研究这些候选相互作用基因在天然噬藻群体中的时空多样性。第三部分将把新的病毒标记方法应用于自然宿主群体，以表征环境中噬藻-聚藻球菌相互作用网络。知识价值：病毒在全球海洋生物地球化学循环中的作用取决于病毒引起的死亡率，据估计，死亡率差异很大。谁感染谁的模式和动态对我们理解这些速率以及病毒在海洋营养循环中所起的作用至关重要。这个项目也将有助于我们对病毒多样性的了解。绝大多数海洋病毒序列与任何已知的多样性都不相似，因此可以合理地得出结论，其中许多基因与宿主识别和感染有关。最后，该项目将开发一种表征自然、不同微生物群落中噬菌体-细菌相互作用的方法，从而为在其他环境中进行类似的病毒研究开辟道路。更广泛的影响：该项目将为15名本科生（包括来自加州少数民族参与科学、工程和数学联盟的学生）、2名研究生和一名博士后提供培训。该项目还将建立在与加州水晶湾州立公园共同开发的科学教育实习项目的基础上。公园每年接待超过120万游客和10,000名K-12学生。该计划的成果将是放置在公园海洋研究设施的专题科学教材，供初高中教师和学生使用。这些工具包将把海洋微生物研究与加州和国家科学标准的标准课程联系起来，教育公众了解美国国家科学基金会的这项研究，并协助培训科学、技术、工程和数学（STEM） K-12教师。研究结果将在包括美国教育研究协会（AERA）和美国国家科学教学研究协会（NARST）在内的全国性会议上发布，而课程和视频制作将在UCI艺术科学和可持续发展学习中心的网站上发布。

Viral-induced mortality of marine microorganisms alters the quantity and quality of pools of dissolved organic matter in the oceans, shuttling organic matter back into the microbial loop and away from the larger marine food web. A major hindrance to understanding the role of viruses in biogeochemical cycling is that we know surprisingly little about which viruses infect which bacteria in the marine environment. In this project, a network-based framework will be used to investigate marine phage-bacteria interactions in complex, multispecies communities. The research focuses on cyanophages, viruses that infect Synechococcus, an ecologically important cyanobacterium in the oceans. There are three parts of the project. The first part will identify genetic signatures of cyanophage-Synechococcus interactions by using laboratory evolution experiments and genomic sequencing. The second part will examine the temporal and spatial diversity of these candidate interaction genes in natural cyanophage populations, by comparing the full genome sequences of hundreds of isolates previously collected over many years. The third part will adapt the new method of viral-tagging to natural host populations to characterize cyanophage-Synechococcus interaction networks in the environment. Intellectual Merit: The role of viruses in global marine biogeochemical cycles depends on viral-induced mortality rates, which have been estimated to vary widely. The pattern and dynamics of who infects whom are central to our understanding of these rates as well as the role viruses play in marine nutrient cycling. This project will also contribute generally to our knowledge about viral diversity. The vast majority of marine viral sequences are not similar to any known diversity, and it is reasonable to conclude that many of these genes have to do with host recognition and infection. Finally, this project will develop a method of characterizing phage-bacteria interactions in natural, diverse microbial communities, thereby opening avenues for similar studies of viruses in other environments.Broader Impacts: The project will provide training for 15 undergraduate students (including students from the California Alliance for Minority Participation in Science, Engineering, and Mathematics), 2 graduate students and a postdoc. The project will also build on a science-education internship program that was developed with Crystal Cove State Park in California. The Park is host to more than 1.2 million visitors and 10,000 K-12 students each year. The outcome of this program will be topical science teaching kits that reside in the Marine Research Facility of the Park to be used by middle and high school teachers and students. These kits will connect marine microbiological research to the standards-based curricula of California and National Science Standards, educate the public on this NSF research and assist in the training of Science, Technology, Engineering, and Math (STEM) K-12 teachers. The results will be disseminated at national conferences, including American Educational Researchers Association (AERA) and National Association of Research on Science Teaching (NARST), while the curriculum and video productions will be hosted on the website of the UCI Center for Learning in the Arts Sciences and Sustainability.