Deciphering the ecology of aquatic single-stranded DNA phages (Microviridae/Gokushovirinae)

噬菌体(感染细菌的病毒)是所有生态系统中丰富和动态的组成部分。通过感染细菌，噬菌体可以影响碳循环和营养循环，影响细菌多样性，并在基因转移中发挥重要作用。噬菌体有两种变种--双链和单链DNA(SsDNA)。人们一直认为单链DNA噬菌体在水生生态系统中并不重要，但该团队最近的研究表明并非如此。作为对单链DNA噬菌体在内陆水域中作用的第一次研究，拟议的研究将揭示以前被忽视的水生生态系统的一个组成部分。项目成果将提供有关天然淡水生境中单链DNA噬菌体的丰度、多样性和生态的第一次洞察。除了培训研究生和本科生外，外联活动还将通过为南佛罗里达大学八年级女生海洋学夏令营创建动手学习模块以及通过参与当地女童子军的参与，鼓励十几岁的女孩从事STEM领域的工作。这项提案将通过重点研究佛罗里达州的两个地面供水泉水和相关的水生生态系统，研究被称为GokushoVirus病毒(微病毒科、Gokushovirinae亚科)的单链DNA噬菌体的多样性和生态作用。其中一个泉的初步研究表明，单链DNA噬菌体多样性较低，简化了时空变异性的评估，并提高了区分特定噬菌体-宿主关联的可能性。这项研究结合了定量和定性的方法来分析Gokusho病毒及其潜在宿主的分布，以及基于实验室的微观研究，以提供对这一独特病毒组的生态的洞察。通过对每个泉水系统中三个地点的每日、每日和每月采样，该项目将确定戈库肖病毒丰度和多样性的时间和空间模式，以检验这样的假设，即泉水保持稳定、低多样性的戈库肖病毒群落，而戈库肖病毒多样性和丰度表现出季节性波动，远离环境变化更明显的泉水。通过对寄主和噬菌体群落的同步序列分析、单细胞技术、微观世界实验、细菌呼吸和代谢多样性的测量、诱导分析和培养尝试，该项目将限制Gokusho病毒的潜在宿主范围，并确定它们在水生态系统中的生态作用。这些实验将检验这样的假设，即单链DNA噬菌体通过感染特定的细菌宿主来改变细菌群落组成和生态系统功能，其中一些细菌宿主能够溶原化。这些目标的实现将改变水生微生物生态，使单链DNA病毒成为水生病毒群中众所周知的组成部分。

Phage (viruses that infect bacteria) are abundant and dynamic components of all ecosystems. Through infection of bacteria, phage can affect carbon and nutrient cycles, influence bacterial diversity, and play important roles in gene transfer. Phage come in two varieties - those with double stranded versus those with single-stranded DNA (ssDNA). It had been assumed that ssDNA phage were not important in aquatic ecosystems, but recent studies by this team suggest otherwise. As the first study of the role of ssDNA phage in inland waters, the proposed research will shed light on a previously overlooked component of aquatic ecosystems. Project results will provide the first insight regarding the abundance, diversity, and ecology of ssDNA phages in natural freshwater habitats. In addition to training graduate and undergraduate students, outreach will encourage teenage girls to pursue STEM fields through creating hands-on learning modules for an Oceanography Camp for 8th Grade Girls at the University of South Florida and through involvement with local Girl Scout troops. This proposal will study the diversity and ecological roles of the ssDNA phages known as gokushoviruses (family Microviridae, subfamily Gokushovirinae) by focusing on two ground-fed springs and associated aquatic ecosystems in Florida. Preliminary studies in one of these springs indicated low ssDNA phage diversity, simplifying evaluations of spatiotemporal variability and improving the likelihood of discriminating specific phage-host associations. This research combines quantitative and qualitative methods to analyze the distribution of gokushoviruses and their potential hosts, as well as lab-based microcosm studies to provide insight into the ecology of this unique viral group. Through diel, daily, and monthly sampling from three sites in each spring system, this project will determine the temporal and spatial patterns of gokushovirus abundance and diversity to test the hypothesis that the springs maintain a stable, low-diversity gokushovirus community, while gokushovirus diversity and abundance display seasonal fluctuations farther from the springs where environmental variation is more pronounced. Through simultaneous sequence-based analysis of host and phage communities, single-cell techniques, microcosm experiments, measurements of bacterial respiration and metabolic diversity, induction assays, and culturing attempts, this project will constrain the potential host range of gokushoviruses and determine their ecological roles in aquatic ecosystems. These experiments will test the hypothesis that ssDNA phages modify bacterial community composition and ecosystem function through infection of specific bacterial hosts, some of which they are able to lysogenize. Completion of these goals will transform aquatic microbial ecology by enabling the inclusion of ssDNA viruses as a well-understood, integral component of the aquatic virome.