DISSERTATION RESEARCH: Amphibian Parasites and Immunity: Newts as a Model for Understanding Amphibian Disease Ecology

世界范围内青蛙和蝾螈的数量正在减少，其中一些显然是由于出现了新的或更严重的疾病。虽然这些流行病的确切原因尚不清楚，但它们很可能受到人类引起的环境变化的影响，这些变化影响了两栖动物对病原体的暴露和易感性。温度依赖性免疫可能对两栖动物的疾病动态特别重要，导致它们在春季或气候条件变化时更容易受到感染。本项目以红点蝾螈（一种常见的温带蝾螈）为模型物种，研究：(1)两栖动物感染和免疫的季节性；(2)导致最近两栖动物死亡的类鱼舌类真菌爆发的因素；(3)蝾螈寄生虫群落结构的生态过程。捕获-标记-再捕获方法结合实验室和实地实验，将用于检验解释在对蝾螈种群及其寄生虫的空间和季节调查中观察到的模式的假设。本研究将对季节温度波动对两栖动物免疫防御的影响、一种重要真菌病原体的传播动态以及两栖动物寄生虫的群落生态学提供深入的见解。研究蝾螈的多种免疫参数和寄生虫物种将对我们理解人类引起的环境变化如何影响两栖动物种群的疾病动态产生更广泛的影响，为两栖动物疾病生态学的一般原理提供见解。本项目将支持一名博士研究生的论文研究。

Frog and salamander species are declining worldwide, some apparently due to the emergence of new or more severe diseases. While the precise causes of these epidemics are unclear, they are likely to be influenced by human-induced environmental changes affecting both exposure and susceptibility of amphibians to pathogens. Temperature-dependent immunity may be particularly important to disease dynamics in amphibians, leading to increased susceptibility to infection in springtime or under changing climatic conditions. This project uses the Red-spotted newt, a common temperate salamander, as a model species for studying: (1) seasonality in infection and immunity in amphibians, (2) factors leading to outbreaks of an Ichthyophonus-like fungus implicated in recent amphibian die-offs, and (3) ecological processes structuring the newt parasite community. Capture-mark-recapture methods coupled with lab and field experiments will be used to test hypotheses which explain patterns observed in spatial and seasonal surveys of newt populations and their parasites. This research will provide insights into the effects of seasonal temperature fluctuations on amphibian immune defenses, the transmission dynamics of an important fungal pathogen, and the community ecology of amphibian parasites. Studying multiple immune parameters and parasite species in newts will lead to a broader impact on our understanding of how human-induced environmental changes affect disease dynamics in amphibian populations, by providing insight into general principles of amphibian disease ecology. This project will support the dissertation research of a doctoral candidate.