Opening the black box of viruses in aquatic systems

打开水生系统中病毒的黑匣子

• 批准号: RGPIN-2015-05896
• 负责人: Suttle, Curtis
• 金额: $ 4.59万
• 依托单位: University of British Columbia
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=691170
• 关键词: Opening; black; box; viruses; aquatic

At abundances of 106 to 108 ml-1, viruses are the most numerous and diverse "life" in the oceans. End-to-end, they would stretch 107 light years, farther than the nearest 60 galaxies. It is estimated they infect ~1023 cells s-1, and kill 10 to 20% of the ocean's biomass daily, resulting in 6 to 26% of carbon fixed by phytoplankton passing through the viral shunt. Clearly, viruses are major players in mortality, nutrient cycling and structuring planktonic communities; yet, the composition and function of viruses in aquatic systems is largely unknown. The long-term goal of my research is to understand the enormous genetic and biological diversity of aquatic viruses and their impact on ecosystems. The proposed research will advance our understanding of aquatic viruses and their function through virus discovery and quantifying their impact on mortality. ******In the virus-discovery theme, traditional approaches will be used to isolate novel viruses that infect ecologically important taxa, while state-of-the-art single-virion genomic and metagenomic approaches will be employed to characterize the isolates and in situ virus communities. Four projects comprise the viral discovery component: 1) Isolation and characterization of new host-virus systems for ecologically important microbial taxa will provide model systems for studying host-virus interactions. We will focus on giant viruses, because metagenomic data indicate they are widespread in aquatic systems, but there are few in culture infecting planktonic protists. 2) We will employ single-virion genomic technologies to sequence uncultured representative viruses from a range of natural environments. This will help close the sequence space for aquatic viruses and provide genomic context for short-read metagenomic data. 3) Metagenomic analysis of aquatic RNA virus communities will reveal the most abundant RNA viruses across a range of aquatic systems, allow the assembly of novel genomes, and provide context to targeted amplicon sequencing data from other studies. 4) Determining the composition of viruses associated with major taxa of zooplankton and their potential impact.******The second theme explores the impact of viruses on microbial mortality. Using a targeted sequencing technique to estimate taxon-specific viral mediated mortality across systems we will determine which prokaryotic and eukaryotic microbial taxa are most subject to viral lysis, and test the hypothesis that most lysis is occurring in productive but relatively rare members of the community.******Collectively, this research program advances our understanding of viruses in aquatic systems by bringing new virus-host systems into culture, characterizing viral communities and determining taxon-specific lysis in microbial communities.

病毒的丰度为 106 至 108 ml-1，是海洋中数量最多、种类最多的“生命”。它们从头到尾绵延 107 光年，比最近的 60 个星系还要远。据估计，它们感染约 1023 个 s-1 细胞，每天杀死 10% 至 20% 的海洋生物量，导致浮游植物通过病毒分流固定 6% 至 26% 的碳。显然，病毒是死亡率、营养循环和浮游生物群落结构的主要参与者。然而，水生系统中病毒的组成和功能在很大程度上尚不清楚。我研究的长期目标是了解水生病毒巨大的遗传和生物多样性及其对生态系统的影响。拟议的研究将通过病毒发现和量化其对死亡率的影响来增进我们对水生病毒及其功能的理解。 ******在病毒发现主题中，将使用传统方法分离感染生态重要类群的新型病毒，同时将采用最先进的单病毒体基因组和宏基因组方法来表征分离株和原位病毒群落。病毒发现部分由四个项目组成：1）对生态上重要的微生物类群的新宿主病毒系统的分离和表征将为研究宿主病毒相互作用提供模型系统。我们将重点关注巨型病毒，因为宏基因组数据表明它们在水生系统中广泛存在，但在培养物中很少感染浮游原生生物。 2）我们将采用单病毒体基因组技术对来自一系列自然环境的未培养的代表性病毒进行测序。这将有助于关闭水生病毒的序列空间，并为短读宏基因组数据提供基因组背景。 3) 水生RNA病毒群落的宏基因组分析将揭示一系列水生系统中最丰富的RNA病毒，允许组装新的基因组，并为来自其他研究的目标扩增子测序数据提供背景。 4) 确定与浮游动物主要类群相关的病毒组成及其潜在影响。******第二个主题探讨病毒对微生物死亡率的影响。使用靶向测序技术来估计跨系统的分类单元特异性病毒介导的死亡率，我们将确定哪些原核和真核微生物分类单元最容易受到病毒裂解，并检验大多数裂解发生在富有生产力但相对稀有的群落成员中的假设。 ******总的来说，该研究计划通过将新的病毒宿主系统引入培养物、描述病毒群落特征并确定微生物群落中分类单元特异性裂解，增进了我们对水生系统中病毒的理解。