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而动态的组成部分。噬菌体通过感染细菌，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——双链DNA和单链DNA （ssDNA）。人们一直认为ssDNA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。作为对内陆水域中ssDNA噬菌体作用的首次研究，拟议的研究将揭示以前被忽视的水生生态系统组成部分。项目结果将首次提供有关天然淡水栖息地中ssDNA噬菌体的丰度、多样性和生态学的见解。除了培训研究生和本科生，外展活动还将鼓励十几岁的女孩通过为南佛罗里达大学的八年级女孩海洋学夏令营创建动手学习模块，并通过参与当地女童子军，来追求STEM领域。该提案将研究被称为gokushoviruses（微病毒科，Gokushovirinae亚科）的ssDNA噬菌体的多样性和生态作用，重点研究佛罗里达州的两个地面泉水和相关的水生生态系统。其中一个春季的初步研究表明，低ssDNA噬菌体多样性，简化了时空变异性的评估，提高了区分特定噬菌体-宿主关联的可能性。本研究结合定量和定性方法分析了gokushovirus及其潜在宿主的分布，以及基于实验室的微观研究，以深入了解这一独特病毒群的生态学。通过在每个春季系统的三个地点进行日、日、月采样，该项目将确定谷草病毒丰度和多样性的时空格局，以验证以下假设：春季保持稳定、低多样性的谷草病毒群落，而谷草病毒的多样性和丰度显示出远离环境变化更明显的春季的季节性波动。通过宿主和噬菌体群落的同步序列分析、单细胞技术、微观实验、细菌呼吸和代谢多样性测量、诱导试验和培养尝试，该项目将限制gokushoviruses的潜在宿主范围，并确定其在水生生态系统中的生态作用。这些实验将验证ssDNA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的假设，其中一些它们能够溶原。这些目标的完成将改变水生微生物生态，使ssDNA病毒成为水生病毒群的一个很好理解的组成部分。

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.