Ecology and evolution of host/parasite interactions

寄生是地球上最常见的生活方式。这一现象的一个标志是宿主和寄生虫之间为满足其生存和繁殖需要而存在的复杂而密切的相互作用。虽然结果往往涉及两个对立方之间的冲突，但许多结果可以解释为满足两个伙伴截然不同的目标的妥协。我们通常不知道特定的宿主-寄生虫相互作用在这个连续统一体中的位置，这使得很难解释进化将如何在“新的”宿主/寄生虫组合中进行，这些组合经常主导我们的人类栖息地。我使用实验室操作，系统发育分析，野外工作和现代分子工具的组合来研究宿主和寄生虫之间的相互作用。在我们的主要模型系统中，我们使用常见的小鱼和他们的脑包囊吸虫，以评估主机的反应策略，一方面，和寄生虫的开发策略。这些蠕虫在脑组织内有一个专门的进食阶段，这会降低宿主的生理和行为表现。我们现在正在结合系统发育比较和实验暴露，以跟踪幼虫喂养阶段的演变，并测试生命周期中其他阶段的生命史权衡。在同一系统内，我们将结合联合收割机实验室和现场实验，以评估宿主通过完全避免感染阶段而使感染成本最小化的程度。在这里，我们问鱼是否可以检测到与感染相关的“恐惧因素”，然后学会通过降低风险的抗寄生虫行为做出反应。除了利用宿主资源外，许多寄生虫还利用宿主行为来满足其传播需求。我们对潜在的机制了解甚少。一个引人注目的例子是一种吸虫的幼虫阶段，它感染了蚂蚁的大脑，导致它们在一天中寒冷的时候爬上植被并夹紧。我们将使用现代蛋白质组学工具，涉及寄生虫和宿主组织，以揭示导致“僵尸蚂蚁”行为改变的机制。

Parasitism is the most common lifestyle on earth. One hallmark of the phenomenon is the complex and intimate interplay that exists between host and parasite to meet their survival and reproduction needs. Although the outcome often involves conflict between two antagonists, many outcomes can be interpreted as a compromise that meet the contrasting aims of the two partners. We often do not know where particular host-parasite interactions fit on this continuum, making it difficult to interpret how evolution will proceed in 'new' host/parasite combinations that so often dominate our anthropogenic habitats. I use a combination of laboratory manipulations, phylogenetic analyses, field work, and modern molecular tools to study the interplay between hosts and parasites. In our main model system, we use common minnows and their brain-encysting flukes to evaluate host response strategies on the one hand, and parasite exploitation strategies on the other. These worms have an obligate feeding phase within brain tissue that reduce the hosts' physiological and behavioural performance. We are now combining phylogenetic comparisons and experimental exposures to track the evolution of the larval feeding stage and testing for life-history trade-offs with other stages in the life-cycle. Within this same system, we will combine laboratory and field experiments to assess the extent to which hosts can minimize the costs of infection by avoiding infective stages all-together. Here, we ask whether fish can detect 'fear factor' associated with infection and then learn to respond via anti-parasite behaviours that reduce risk. In addition to exploiting host resources, many parasites exploit host behaviours to meet their transmission needs. We have a poor understanding of underlying mechanisms. One spectacular example involves the larval stages of a fluke that infects the brains of ants, causing them to ascend vegetation and clamp-on during cold hours of the day. We will use modern proteomics tools involving both parasite and host tissue to uncover the mechanisms leading to the altered behaviours of the 'zombie ants'.