Mineral nutrition of host-parasite interactions

寄生是加拿大大多数（如果不是全部的话）水生环境的共同特征。尽管如此，寄生虫及其对许多水生动物（鱼类除外）的影响在很大程度上仍未得到研究。营养可能是水生动物与其寄生虫之间相互作用的一个重要组成部分。研究表明，特定的矿物元素（氮和磷）在动物生长中起着核心作用，而水生动物的食物中往往缺乏这些元素。在这个项目中，我将研究矿物质营养在动物-寄生虫相互作用的关键方面的作用。特别是，我将研究一种常见的湖泊甲壳类动物水蚤对细菌感染的易感性是如何随着食物质量的变化而变化的。此外，我将把细菌寄生虫的繁殖成功与水蚤所消耗的食物质量联系起来。这些对宿主-寄生虫流行病学的影响可能显著改变水蚤种群的大小。我将探讨在不同食物质量的条件下，水蚤的种群周期在存在和不存在寄生虫感染的情况下是如何变化的。我将把这个关于动物寄生的研究扩展到安大略省中南部的湖泊。在这些湖泊中，我将研究动物寄生模式与湖泊地理和水质的关系。这项工作将帮助我们了解加拿大湖泊生态系统中水生动物传染病的基本机制。

Parasitism is a common feature of most, if not all, aquatic environments of Canada. Despite this, parasites and their effects on many aquatic animals, with the exception of fish, remain largely unstudied. Nutrition is likely to be an important component of these interactions between aquatic animals and their parasites. It has been shown that particular mineral elements (nitrogen and phosphorus) play a central role in animal growth and can often be deficient in the food of aquatic animals. In this project, I will examine the role of mineral nutrition on key aspects of animal - parasite interactions. In particular, I will examine how susceptibility to bacterial infection varies with the food quality consumed by a common lake crustacean, Daphnia. In addition, I will relate the reproductive success of the bacterial parasite to the food quality consumed by Daphnia. These effects on host-parasite epidemiology could significantly alter the size of Daphnia populations. I will explore how population cycles of Daphnia vary in the presence and absence of parasitic infection under conditions of different food quality. I will extend this research on animal parasitism to the lakes of south central Ontario. In these lakes, I will examine how patterns of animal parasitism relate to lake geography and water quality. This work will help us understand the basic mechanisms underlying infectious disease of aquatic animals in Canada's lake ecosystems.