Viral discovery and unlocking the role of viruses in taxon-specific microbial mortality

病毒发现并揭示病毒在分类单元特异性微生物死亡率中的作用

• 批准号: RGPIN-2020-06519
• 负责人: Suttle, Curtis
• 金额: $ 5.03万
• 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: 2021
• 资助国家: 加拿大
• 起止时间: 2021-01-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=741261
• 关键词: Viral; discovery; unlocking; role; viruses

More than 90% of the living material in the ocean, by weight, is microscopic, and these microbes produce about half the planet's oxygen. Within this microbial milieu are 1 to 100 million viruses /mL, the most numerous "life" in the sea. As obligate pathogens, viruses can only reproduce by infecting cellular organisms; they are estimated to kill ~20 % of life in the ocean daily. Thus, viruses are major players in mortality, biogeochemical cycling and structuring marine ecosystems. Despite their importance, we still know relatively little about aquatic viruses and their impact on the mortality of specific organisms. For ~30 years, my laboratory has been a leader in the study of aquatic viruses and their ecosystem effects. The proposed research builds on this foundation, and focuses on virus discovery and quantifying the role of viruses in mortality, two areas where new knowledge has the potential for a large impact. There are still many viruses to be discovered, and many organisms for which viruses are unknown or poorly characterized. Giant Viruses (GVs) are a group of viruses where the potential for making high-impact discoveries is high. These leviathans of the viral world have the largest genomes of any viruses and surpass the size and complexity of those of some bacteria, bridging the gap between cells and viruses. These viruses are only known to infect protists, which include major groups of phytoplankton and zooplankton. Yet, only a few GVs have been isolated that infect plankton, even though sequencing data indicates they are widespread and abundant. Isolating more GVs may shed light on their origin and help elucidate their biology and function in nature. Another area that is ripe for viral discovery are groups of organisms for which no known viruses exist. Typically, many different types of viruses infect a single organism; yet, of almost 200 recognized bacterial phyla, viruses are only known for 39 of them. Hence, there is a high probability of discovering new viral lineages that have different biological properties and code for unknown proteins. The final area of viral discovery is viruses associated with copepods, crustacean zooplankton that are a food source for fish, but which can also be fish pathogens and potential vectors for disease. Identifying copepod viruses will allow us to track them in host populations, a first step in determining their relationship to disease. The other area of focus is on quantifying the impact of viruses on microbial mortality. Viruses kill about 20% of microbes each day, but are typically very host specific, so their impact will be selective. As different microbes have different ecosystem functions the effects may be broad. Newly developed methods will be used to look at the mortality of specific microbial taxa. This will allow us to test the hypothesis that the fastest growing microbes are subject to the greatest lysis, which has important implications for population dynamics.

按重量，海洋中90％以上的生物是微观的，这些微生物产生了大约一半的行星氧气。在这个微生物环境中，有1至1亿个病毒 /毫升，是海洋中最多的“生命”。作为强制性病原体，病毒只能通过感染细胞生物来再现。据估计，它们每天在海洋中杀死约20％的生命。因此，病毒是死亡率，生物地球化学循环和结构海洋生态系统的主要参与者。尽管它们的重要性，但我们仍然对水生病毒及其对特定生物的死亡的影响相对较少了解。大约30年来，我的实验室一直是水生病毒研究及其生态系统影响的领导者。拟议的研究基于该基础，并着重于病毒发现并量化病毒在死亡率中的作用，这两个领域有两个新知识有可能产生巨大影响的领域。 仍然有许多病毒可以发现，许多病毒的生物是未知或表征不佳的生物。巨型病毒（GVS）是一组病毒，在这种病毒中，产生高影响力的可能性很高。这些病毒世界中的利维亚人具有任何病毒中最大的基因组，超过了某些细菌的大小和复杂性，弥合了细胞和病毒之间的间隙。这些病毒仅感染生物，其中包括浮游植物和浮游动物的主要群体。然而，即使测序数据表明它们广泛而丰富，只有少数GV被隔离而感染了浮游生物。隔离更多的GV可能会阐明其起源，并有助于阐明其在性质上的生物学和功能。病毒发现成熟的另一个区域是没有已知病毒的生物群。通常，许多不同类型的病毒感染了单一生物体。然而，在近200个公认的细菌门中，病毒仅在其中39个闻名。因此，发现具有不同生物学特性和未知蛋白质代码的新病毒谱系的可能性很高。病毒发现的最终区域是与Copepods，Crustacean浮游生物相关的病毒，它们是鱼类的食物来源，但也可以是鱼类病原体和潜在的疾病媒介。识别copepod病毒将使我们能够在宿主人群中跟踪它们，这是确定它们与疾病关系的第一步。重点的另一个领域是量化病毒对微生物死亡率的影响。病毒每天杀死约20％的微生物，但通常非常特定于宿主，因此其影响会具有选择性。由于不同的微生物具有不同的生态系统功能，因此影响可能很广。新开发的方法将用于研究特定微生物类群的死亡率。这将使我们能够检验以下假设：生长最快的微生物受到最大的裂解，这对人群动态具有重要意义。