EAGER: Viruses of the Protozoan Parasites Perkinsus spp.: Isolation and Characterization

牡蛎和蛤蜊经常受到寄生虫的挑战，包括Perkinsus物种。珀金虫属，皮肤病的病原体，可导致养殖和野生双壳类种群的大量死亡，因此具有重要的有害生态和经济后果。Perkinsus是世界动物卫生组织的可报告疾病清单。大多数旨在了解和干预Dermo的研究都集中在两个游戏中：寄生虫和宿主。然而，以前的超微结构研究表明，在寄生虫的细胞核中存在病毒样颗粒。然而，对这些病毒的遗传学、感染机制或对帕金苏斯生态的影响一无所知。对其他寄生原生动物（包括一些人类宿主）的研究揭示了许多有趣的生物学现象，表明有充分的理由预期病毒对帕金虫的繁殖，生活方式和毒力有深远的影响。证明帕金虫属病毒感染。了解宿主对感染的功能反应将代表我们对帕金虫的思维模式的转变。生态学和对双壳类宿主的毒力。此外，它还将为采取新的干预措施对付致病因子打开大门。该项目被认为是高风险高回报，因为到目前为止，令人信服的证据是基于使用电子显微镜进行的超微结构研究，但缺乏信息来评估病毒分离的难易程度。该项目的重点是分离和表征感染Perkinsus spp的病毒。这是了解帕金虫属病毒感染动力学的必要的第一步。细胞和病毒对这种原生动物寄生虫的繁殖和毒力的影响。在这项研究中，工作将集中在三个珀金虫属。(P. marinus、P. chesapeaki和P. olseni），其先前存在病毒感染的证据。研究人员将从已经培养的几种帕金苏斯菌株以及新的帕金苏斯物种中分离出特异性病毒。分离株将努力从这些分离株中建立培养物，并优化病毒在实验室中的繁殖和维持。他们还将进行生长曲线实验，并研究病毒感染对帕金苏斯生理学的影响，以及作为细胞分化的潜在触发因素。在培养物中具有良好表征的模型病毒-宿主系统对于研究影响病毒复制成功和特异性的环境参数至关重要。它还将有助于理解病毒-宿主相互作用的机制及其通过假设驱动的实验操作的生态和生理后果。总的来说，这个项目将有助于评估感染帕金虫的病毒的普遍性。以及它们在塑造这些双壳类寄生虫的生命周期和毒力方面所起的作用。

Oysters and clams are often challenged by parasites, including Perkinsus species. Perkinsus spp., causative of Dermo disease, can lead to mass mortalities of farmed and wild bivalve populations and hence have important detrimental ecological and economic consequences. Perkinsus is on the World Organization for Animal Health's list of reportable diseases. Most of the studies aimed to understand and intervene against Dermo have centered in a game of two: parasite and host. However, previous ultrastructural studies have shown the presence of virus-like particles in the nucleus of the parasite. Yet, nothing is known about these viruses' genetics, mechanism of infection, or consequences on Perkinsus ecology. Research on other parasitic protozoa (including some with human hosts) has revealed many interesting biological phenomena that suggest that there is every reason to expect that viruses have a profound effect on the propagation, life style and virulence of Perkinsus spp. Proving viral infection of Perkinsus spp. and understanding the host's functional responses to infections will represent a paradigm shift in our thinking about Perkinsus spp. ecology and virulence toward their bivalve hosts. Furthermore, it will open the door to new approaches for intervention against the disease-causing agent. This project is considered high risk-high payoff since, thus far, compelling evidence of viruses infectious to Perkinsus is based on ultrastructural studies using electron microscopy, but information to assess ease of virus isolation is lacking. This project focuses on isolating and characterizing viruses that infect Perkinsus spp. This is a necessary first step toward understanding the dynamics of viral infection of Perkinsus spp. cells and the effects of viruses on the propagation and virulence of this protozoan parasite. In this study, work will focus on the three Perkinsus spp. (P. marinus, P. chesapeaki, and P. olseni) for which there is previous evidence of viral infection. The investigators will isolate viruses specific to several Perkinsus strains already in culture as well as from new Perkinsus spp. isolates. Effort will be put in establishing cultures from those isolates and to optimize propagation and maintenance of the viruses in the laboratory. They will also conduct growth curve experiments, and investigate the effect of viral infection on Perkinsus physiology and as a potential trigger for cell differentiation. Having well characterized model virus-host systems in culture is essential to investigate the environmental parameters that affect viral replication success and specificity. It will also aid in understanding the mechanisms of virus-host interactions and their ecological and physiological consequences through hypothesis driven experimental manipulation. Overall, this project will help to evaluate the ubiquity of viruses that infect Perkinsus spp. and the roles they play in shaping the life cycle and the virulence of these parasites of bivalves.