Evolutionary Determinants of Host Range in Parasitic Nematodes

[00:74 . 41]这项拟议的研究将研究果蝇和线虫寄生虫之间的进化关系，包括进化变化的时间尺度，从数百万年到现在种群中正在发生的变化。实验将用8种线虫和24种果蝇进行感染。这些实验与分子系统发育分析相结合，将能够确定宿主系统发育在多大程度上决定了寄生虫的宿主范围，并确定宿主范围如何在这些寄生虫中进化。密切相关的果蝇物种将进行杂交，以揭示对寄生虫抗性的种间差异的遗传基础。这些杂交实验还将揭示对一种寄生虫的抗性是否与对其他寄生虫的抗性在遗传上相关。寄生虫是普遍存在的——但通常被忽视的——自然群落的组成部分，往往对其寄主物种的个体和种群产生重大影响。寄生虫的潜在宿主范围与新发疾病、寄生虫在生物防治计划中的应用以及入侵寄生虫对濒危物种的影响等问题有关。提出的寄生虫宿主范围进化决定因素的研究将有助于发展宿主-寄生虫相互作用的综合理论。

0074141JaenikeThe proposed research will examine the evolution of associations between Drosophila and nematode parasites, encompassing time scales of evolutionary change from of millions of years down to changes ongoing within present-day populations. Experimental infections will be conducted with 8 nematode species and 24 Drosophila species. These experiments, in conjunction with molecular phylogenetic analyses, will allow a determination of the extent to which a parasite's host range is determined by host phylogeny, as well as determination of how host range evolves in these parasites. Closely related Drosophila species will be crossed to uncover the genetic basis of interspecific differences in resistance to parasites. These hybridization experiments will also reveal whether resistance to one parasite species is genetically correlated with resistance to others. Parasites are ubiquitous - but generally overlooked - components of natural communities, often having major effects on the individuals and populations of their host species. The potential host range of a parasite is relevant to the issue of emerging diseases, the use of parasites in biological control programs, and the effect of invading parasites on endangered species. The proposed studies of the evolutionary determinants of parasite host range will contribute to the development of a comprehensive theory of host-parasite interactions.