Unravelling the Complex Interactions of Algal Viruses and Their Hosts

在全球范围内，微藻或浮游植物是最重要的水生初级生产者。它们对人类事务至关重要，因为它们将无机物质转化为有机物质，从而为海洋和淡水食物网提供燃料。它们的生长决定了水生环境的生产力和质量，以及它们对人类的有益利用，例如维持渔业或形成有害的藻华。在20世纪90年代，生物海洋学家发现，感染藻类的病毒在几乎所有的水生环境中都很丰富，其中大多数是高度物种特异性的，可以溶解或杀死它们的藻类宿主。这些发现提出了许多关于病毒对水生食物网的影响及其在藻类生态和进化中的作用的问题。正在进行的研究表明，藻类的病毒感染可以直接或间接地影响物种竞争、水生环境中的营养循环和藻类进化。越来越多的证据表明，藻病毒和它们的宿主以一种动态的方式相互作用，相互影响对方的生长和进化，但它们的相互作用是复杂的，很难预测，因此许多基本问题仍未得到解答。我的研究计划的长期目标是推进藻类病毒与宿主相互作用的知识。这些研究将提高我们预测浮游植物群落组成和动态及其提供的生态系统服务的能力。在接下来的几年里，我的研究团队将专注于我的项目长期目标所包含的具体的、可处理的目标。这些研究包括对藻病毒在环境中的持久性的研究，对我的团队在安大略湖发现并分离的一组藻病毒进行表征，以及对这些病毒的遗传能力和活动进行表征。为了实现这些目标，我们将进行的实验包括基于实验室的培养和环境采样，以及各种分子生物学和细胞生物学工具，如定量PCR，透射电子显微镜，基因组测序和下一代测序促进的基因表达研究。我的研究小组最近分离出感染全球相关淡水微藻的病毒，并发现我们拥有一个由不同病毒和病毒噬菌体组成的联盟，这些病毒共同感染宿主细胞并间接寄生于其他病毒，这大大增强了我们对病毒与藻类相互作用的理解能力！这些项目将为从环境监测到分子生物学等广受欢迎的研究技术提供培训机会。我的研究将通过加强我们对病毒在初级生产中的作用的理解来为水生生态系统模型提供信息，并将告诉我们环境如何影响病毒活动。更广泛地说，我们的研究将有助于提高对病毒生态学和进化以及病毒发病机制的认识。

Globally, microalgae, or phytoplankton, are the most important aquatic primary producers. They are critical to human affairs because they convert inorganic material into organic thereby fueling marine and freshwater food webs. Their growth determines the productivity and quality of aquatic environments, and their beneficial use by human by sustaining fisheries or forming nuisance algal blooms, as examples. In the 1990s, biological oceanographers discovered that viruses infecting algae are abundant in nearly all aquatic environments and most of them are highly species-specific and lyse, or kill, their algal hosts. These discoveries raised many questions about the influence of viruses on aquatic food webs and their role in algal ecology and evolution. Ongoing research has demonstrated that viral infections of algae can directly and indirectly affect species competition, nutrient cycling in aquatic environments, and algal evolution. Evidence is accumulating that algal viruses and their hosts interact in a dynamic manner, each influencing the growth and evolution of the other, yet their interactions are complex and rarely predictable, so many fundamental questions remain unanswered. The long-term goal of my research program is to advance knowledge of algal virus' interactions with their hosts. These studies will enhance our ability to predict the composition and dynamics of phytoplankton communities and the ecosystems services they provide. In the coming years, my research team will focus on specific, tractable objectives encompassed by my program's long-term goal. These include studies of the environmental persistence of algal viruses, characterizing a consortium of algal viruses that my group discovered and isolated from Lake Ontario, and characterizing the genetic capabilities and activities of these viruses. The experiments we will conduct to fulfill these objectives involve laboratory-based cultivation and environmental sampling, and various molecular biology and cell biology tools like quantitative PCR, transmission electron microscopy, and genome sequencing and gene expression studies facilitated by Next-Generation Sequencing. Our ability to advance understanding of virus-algae interactions is greatly enhanced by my research group's recent isolation of viruses that infect a globally relevant freshwater microalgae, and the discovery that we have in our possession a consortium of different viruses and virophages, viruses that co-infect host cells and indirectly parasitizes other viruses! These projects will provide training opportunities for highly sought research techniques ranging from environmental monitoring to molecular biology. My research will inform models of aquatic ecosystems by enhancing our understanding of the role of viruses in primary production and will teach us how the environment influences virus activity. More broadly, our studies will contribute to advancing knowledge of virus ecology and evolution, and viral pathogenesis.