Parasite-modified behaviour in freshwater systems: Context dependence and the ecological role of signaling molecules

淡水系统中寄生虫改变的行为：环境依赖性和信号分子的生态作用

• 批准号: RGPIN-2021-02903
• 负责人: Detwiler, Jillian
• 金额: $ 2.04万
• 依托单位: University of Manitoba
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=744725
• 关键词: Parasite; modified; behaviour; freshwater; systems

Long term goal: Advance our knowledge of the ecological significance of parasite-modified behaviour in aquatic communities. Many parasites can modify their host's behaviour, but the impacts on parasite transmission and other members of aquatic communities are often unclear. Most examples of parasite-mediated behaviour focus on host-parasite interactions that involve trophic transmission. However, parasite transmission is often non-trophic, involving transmission of parasite stages that are short-lived with limited dispersal capabilities. Similar to trophically-transmitted stages, it could be advantageous to modify host behaviour to increase their likelihood of encountering the next host in the life cycle. However, the role of altered behaviour in non-trophic parasite transmission, as well as the mechanisms underlying these changes are mostly unknown. Short-term objectives: 7 HQP will be trained to integrate taxonomic, behavioural, and biochemical data from field and lab experiments to explore the role of chemical communication in parasite-mediated host behaviour by trematode parasites. I focus on freshwater trematodes because they can cause significant disease in humans, livestock, and wildlife. Further, trematodes are ubiquitous in wetlands, many species must infect snails at one point in their life cycle, and many of the latter transmit from snail-snail (e.g. echinostome trematodes). My research program will make several important contributions to understanding factors that affect species interactions. Determining behavioural responses among snails and parasites (Objective 1), and plants (Objective 2) in a controlled lab setting will establish the contexts for species interactions in aquatic communities. Further, these results will disentangle the influence of parasites and infected hosts on behavioural interactions in ecological communities. Using an integrative approach to properly identify snail hosts, trematode parasites, and plants will resolve taxonomic disagreements that impede our ability to understand species interactions. Further, accurate identification is essential to fundamental aspects of trematode biology (e.g. inferences about host specificity and life cycles), parasite epidemiology (e.g. inferences about transmission), and mollusc conservation in freshwater systems (e.g. assessments of gastropod biodiversity and ecosystem health). To explore the mechanistic role of chemical communication in species interactions, I will characterize oxylipins (oxidized fatty acid signaling molecules) from snails, parasites, and plants (Objective 3). These data will suggest which oxylipins influence species interactions. I will determine whether some of these specific molecules or cocktails of molecules explain behavioural patterns (Objective 4). Understanding the role of chemical communication benefits parasite community ecology and epidemiology by improving our knowledge of mechanisms that mediate host-parasite interactions.

长期目标：提高我们对水生群落中寄生虫修饰行为的生态意义的认识。许多寄生虫可以改变宿主的行为，但对寄生虫传播和水生群落其他成员的影响往往不清楚。大多数寄生虫介导的行为的例子集中在宿主-寄生虫的相互作用，涉及营养传播。然而，寄生虫传播往往是非营养性的，涉及传播寄生虫阶段，这些阶段是短暂的，传播能力有限。与营养传播阶段类似，修改宿主行为以增加它们在生命周期中遇到下一个宿主的可能性可能是有利的。然而，行为改变在非营养型寄生虫传播中的作用，以及这些变化的机制大多是未知的。短期目标：7 HQP将接受培训，以整合来自野外和实验室实验的分类学、行为学和生物化学数据，以探索化学通讯在吸虫寄生虫介导的宿主行为中的作用。我专注于淡水吸虫，因为它们可以在人类，牲畜和野生动物中引起重大疾病。此外，吸虫在湿地中无处不在，许多物种必须在其生命周期的某个时刻感染蜗牛，而后者中的许多是通过蜗牛-蜗牛传播的（例如棘口吸虫）。我的研究计划将作出几个重要的贡献，了解影响物种相互作用的因素。在受控的实验室环境中确定蜗牛和寄生虫（目标1）和植物（目标2）之间的行为反应将建立水生群落中物种相互作用的背景。此外，这些结果将解开寄生虫和受感染的主机在生态社区的行为相互作用的影响。使用综合方法正确识别蜗牛宿主、吸虫寄生虫和植物将解决阻碍我们理解物种相互作用能力的分类学分歧。此外，准确的识别是至关重要的吸虫生物学的基本方面（如宿主特异性和生命周期的推论），寄生虫流行病学（如传播的推论），和淡水系统中的软体动物保护（如腹足动物生物多样性和生态系统健康的评估）。为了探索化学通讯在物种相互作用中的机制作用，我将从蜗牛、寄生虫和植物中表征氧脂素（氧化脂肪酸信号分子）（目标3）。这些数据将表明哪些氧脂素影响物种间的相互作用。我将确定这些特定分子或分子混合物中的一些是否可以解释行为模式（目标4）。了解化学通讯的作用有利于寄生虫群落生态学和流行病学，提高我们的知识机制，介导宿主-寄生虫相互作用。