EAGER: Exploration of the presence and ecological significance of viral pathogens in the dynamics of Daphnia, a major pelagic grazer

尽管众所周知，病毒对其他生态系统中的动植物的疾病影响，但人们对淡水生态系统中病毒的身份或生态意义知之甚少。这个急切的项目预测，病毒是湖泊食物网中广泛而重要的组成部分。这项研究将测量感染湖泊中藻类生产的主要消费者--甲壳类浮游动物--的病毒的多样性和丰度。虽然人们对控制湖泊中浮游动物数量的因素了解很多，但所使用的方法几乎完全看不到病毒。直到最近，才开发出能够识别未培养病毒的DNA序列的技术，并允许识别感染浮游动物的病毒。由于目前还没有描述的淡水浮游动物病毒，而且获得病毒DNA序列的成本很高，因此没有足够的背景数据来证明对浮游动物病毒进行更广泛的研究是合理的。因此，这项研究将通过确定感染水蚤的病毒的身份、感染率和分布来开辟新的天地。水蚤是世界各地湖泊中的一种主要淡水甲壳动物。将在纽约的奥奈达湖季节性调查宿主群体中的病毒感染率，那里已经存在关于水蚤动态的大量数据。有关病毒的数据将与浮游动物的出生率和死亡率进行比较，以了解病毒在浮游动物丰度季节变化中的作用。还将检查奥奈达湖和附近其他湖泊中病毒的空间分布情况。这个项目代表了病毒学家和水生生态学家之间的一种新的跨学科合作。新发现的病毒基因将免费提供给更广泛的科学界，以便与其他地方进行的研究进行比较，这将扩大我们对病毒多样性的生态意义的了解。该项目还将涉及几名本科生，他们将接受田间生态学和微生物学的研究培训，包括尖端分子生物学技术。

Little is known about the identity or ecological significance of viruses in freshwater ecosystems, despite well-known disease effects of viruses on plants and animals in other ecosystems. This EAGER project makes the prediction that viruses are a widespread and important component of the food web of lakes. The research will measure the diversity and abundance of viruses that infect the dominant consumers of algal production in lakes, the crustacean zooplankton. While much is understood about the factors regulating the abundance of zooplankton in lakes, viruses have been almost entirely invisible to the approaches used. It is only recently that techniques have been developed capable of identifying the DNA sequences of uncultivated viruses, and permitting identification of viruses that infect zooplankton. Because there are currently no described viruses of freshwater zooplankton, and because of the high cost of obtaining viral DNA sequences, sufficient background data do not exist to justify a wider study of zooplankton viruses. Thus, this research will break new ground by determining the identity, infection rate, and distribution of viruses infecting Daphnia, a dominant freshwater crustacean in lakes world-wide. The viral infection rate within host populations will be investigated seasonally in Oneida Lake, New York, where extensive data on Daphnia dynamics already exist. Data on viruses will be compared with birth and death rates of zooplankton to understand the role of viruses in seasonal changes of zooplankton abundance. The spatial distribution of viruses in Oneida Lake, and in other nearby lakes will also be examined. This project represents a new, interdisciplinary collaboration between a virologist and an aquatic ecologist. Newly discovered viral genes will be made freely available to the wider scientific community for comparison to studies conducted elsewhere, which will expand our knowledge of the ecological significance of viral diversity. This project will also involve several undergraduate students who will receive research training in field ecology and microbiology, including cutting-edge molecular biological techniques.