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: 2021
• 资助国家: 加拿大
• 起止时间: 2021-01-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=742275
• 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：增进我们对水生群落中寄生虫改变行为的生态意义的了解。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。寄生虫介导的行为的大多数例子都集中在涉及营养传递的宿主与寄生虫的相互作用上。然而，寄生虫传播通常是非营养性的，涉及寄生虫阶段的传播，这些阶段寿命短暂，传播能力有限。与营养传播阶段类似，改变宿主行为以增加其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，行为改变在非营养性寄生虫传播中的作用以及这些变化背后的机制大多未知。短期目标：7 HQP 将接受培训，整合来自现场和实验室实验的分类学、行为和生化数据，以探索化学通讯在吸虫介导的宿主行为中的作用。我关注淡水吸虫，因为它们可以给人类、牲畜和野生动物带来严重的疾病。此外，吸虫在湿地中普遍存在，许多物种必须在其生命周期的某一时刻感染蜗牛，并且后者中的许多是通过蜗牛传播的（例如棘口吸虫）。我的研究计划将为理解影响物种相互作用的因素做出一些重要贡献。在受控实验室环境中确定蜗牛和寄生虫（目标 1）以及植物（目标 2）之间的行为反应将为水生群落中的物种相互作用建立背景。此外，这些结果将阐明寄生虫和受感染宿主对生态群落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，准确识别对于吸虫生物学（例如关于宿主特异性和生命周期的推论）、寄生虫流行病学（例如关于传播的推论）和淡水系统中的软体动物保护（例如腹足动物生物多样性和生态系统健康的评估）的基本方面至关重要。为了探索化学通讯在物种相互作用中的机制作用，我将表征来自蜗牛、寄生虫和植物的氧脂质（氧化脂肪酸信号分子）（目标 3）。这些数据将表明哪些氧脂质影响物种相互作用。我将确定这些特定分子或分子混合物是否可以解释行为模式（目标 4）。了解化学通讯的作用可以提高我们对介导宿主与寄生虫相互作用的机制的了解，从而有益于寄生虫群落生态学和流行病学。