EAGER: Exploring phylogenetic diversification of phycodnaviruses across aquatic ecosystems in the Puget Sound region

病毒是地球上最丰富、最广泛和最多样化的生物实体。迄今为止，大多数病毒都是从动植物健康的角度进行深入研究的。然而，这些病毒只是地球上病毒生物多样性的一小部分，因此地球上绝大多数病毒仍未被探索。研究病毒多样性是生物学中的一项重大挑战，对理解地球生物圈具有重要意义。为了应对这一挑战，该项目将研究藻DNA病毒，这是一组非常多样化的病毒，感染世界各地湖泊，河流和海洋中的藻类。将在湖泊中探索藻DNA病毒的多样性和种群动态，这些湖泊是受当地和区域环境变化影响的重要自然资源。这项研究的结果将具有广泛的重要性，因为这些病毒会影响藻类水华，并最终影响湖泊内营养物质的循环。对藻DNA病毒的研究将对其他科学家有用，并为淡水资源的管理提供有价值的信息。这项研究将通过发现新的病毒和确定驱动湖泊中病毒多样性的环境条件来填补我们知识的根本空白。这项研究还将为培养本科生提供一个强有力的平台，使他们掌握广泛的科学方法，并提高学生和公众对湖泊中隐藏的生物多样性的认识。藻DNA病毒提供了一个模型系统，用于探索基于其极端多样性的多样性的系统发育模式（~ 350，000“物种”）、高丰度、生态作用、快速周转率和地理分布。 利用成熟的宏基因组和系统发育方法，在普吉湾地区的创新纵向调查将被用来发现生态和系统发育的多样性藻DNA病毒在不同的营养水平和主机组成的淡水生态系统。除了发现的藻DNA病毒谱系，本研究测试的假设，即藻DNA病毒的多样性和丰度（发病，高峰期，下降）的模式受到湖泊之间的水环境条件的变化。该项目将通过两种方法表征藻DNA病毒的多样性：聚合酶B基因的靶向测序和来自城市和荒野湖泊环境DNA样本的藻DNA病毒全基因组测序。系统发育，生物信息学和DNA序列和湖沼措施的统计分析将用于确定病毒多样性，季节性和环境变量之间的模式和关系。这项研究有望发现具有独特基因组结构的新型藻DNA病毒谱系，湖泊内和湖泊之间的高水平病毒多样性，以及新型病毒谱系出现产生与季节和/或地理相关的新物种组合的明确例子。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Viruses are the most abundant, widespread, and diverse biological entities on earth. To date most viruses have been intensely studied in light of animal and plant health. Yet, these viruses are a small fraction of the earth's total viral biodiversity, and as a result the vast majority of viruses on earth remain unexplored. Studying virus diversity is a major challenge in biology with important consequences for understanding the earth's biosphere. To address this challenge, this project will study phycodnaviruses, an exceptionally diverse group of viruses that infect algae found in lakes, rivers, and oceans around the world. Phycodnavirus diversity and population dynamics will be explored in lakes which are critical natural resources impacted by local and regional environmental changes. The results of the study will be of broad importance as these viruses affect algal blooms and ultimately the cycling of nutrients within lakes. The study of phycodnaviruses will be of use to other scientists and provide valuable information for the management of freshwater resources. The research will fill fundamental gaps in our knowledge by discovering novel viruses and determining the environmental conditions driving virus diversity in lakes. This research will also provide a powerful platform for training undergraduate students in a broad range of scientific methods and enhance both student and public appreciation for the hidden biodiversity within lakes.Phycodnaviruses provide a model system for exploring phylogenetic patterns of diversification based on their extreme diversity (~350,000 'species'), high abundances, ecological roles, rapid turnover rates, and biogeographic distributions. Using well-developed metagenomic and phylogenetic methods, an innovative longitudinal survey in the Puget Sound region will be used to discover the ecological and phylogenetic diversification of phycodnaviruses across freshwater ecosystems that vary in nutrient levels and host composition. In addition to the discovery of phycodnavirus lineages, this research tests the hypothesis that patterns of phycodnavirus diversity and abundance (onset, peak, and decline) are influenced by changes in aquatic environmental conditions among lakes. The project will characterize phycodnavirus diversity through two approaches: targeted sequencing of the polymerase B gene and phycodnaviral whole-genome sequencing from environmental DNA samples across urban and wilderness lakes. Phylogenetic, bioinformatic, and statistical analyses of DNA sequences and limnological measures will be used to identify patterns and relationships between viral diversity, seasonality, and environmental variables. This research is expected to discover novel phycodnavirus lineages with unique genome architectures, high levels of viral diversity within and between lakes, and clear examples where novel viral lineages emerge to generate new species assemblages linked with season and/or geography.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.