Coevolution in simple and complex host-parasite systems. CLUSTER: "Evolutionary genetics of three-spined stickleback - parasite interactions"

该项目扩展并建立在第一阶段项目（Bakker BA 2885/3-1：简单和复杂宿主-寄生虫系统中的共同进化）的结果之上，在该项目中，使用三刺棘鱼Gasterosteus aculeatus及其具有直接生命周期的寄生虫之一，外寄生单殖三代虫Gyrodactylus spp.，和一种具有复杂生命周期的双殖吸虫Diplostomum spp.在苏格兰外赫布里底群岛的北尤伊斯特岛上，许多孤立的湖泊中，以鸟类为最终宿主的鸟类。使用来自具有发育良好的育种着色的种群之一的鱼，在实验室中使用全同胞/半同胞育种设计进行实验感染。雄性繁殖色和生殖行为进行了量化。该数据集将提供关于宿主抗性的可进化性和性选择在宿主抗性进化中的作用的信息。在第二阶段的项目中，重点将放在生态的主机macroparasis在这个系统中的相互作用和寄生虫感染性的变化。北尤伊斯特的湖泊有两种不同的生境类型：在该岛的东部和中部，湖泊被茶染和酸性，而在西部，湖泊是清澈和碱性的。将在三个不同的水平上研究生态对宿主-大型寄生虫相互作用的影响。首先，第一阶段项目的刺鱼及其三代虫和双口虫寄生虫的地理数据集将被扩展，并与水质（pH值，能见度）和鱼类种群大小等生态变量相关，作为遗传变异的代理。这种分析将深入了解宿主-寄生虫共同进化的生态约束。第二，实验室饲养的全同胞/半同胞后代的人口几乎没有发达，单调的育种着色的实验感染，相比，在第一阶段项目中的彩色男性类似的实验，说明在宿主抗性的进化中的性选择的作用的生态限制。第三，实验室饲养的刺鱼种群之一的后代将暴露于寄生虫从不同的洛克斯使用当地，特定的湖泊水，以建立种群间的寄生虫感染性的变化。本实验将用三代虫进行，当在洛克斯湖中收集到足够多的释放囊蚴的蜗牛时，也用双口虫进行。感染性的变化将与生态因素有关，如水质（pH值，能见度），鱼类种群大小和雄性繁殖颜色的阐述。总之，这三种不同的方法将增加我们对生态学在宿主-寄生虫相互作用进化中的作用的理解。

This project extends and builds upon the results of the phase I project (Bakker BA2885/3-1: Coevolution in simple and complex host-parasite systems), in which a phylogeographic analysis using microsatellites of three-spined sticklebacks, Gasterosteus aculeatus, and one of its parasites with a direct life cycle, the ectoparasitic monogenean Gyrodactylus spp., and one with a complex life cycle, the digenean trematode Diplostomum spp. that uses birds as final hosts, of numerous isolated lakes on the island of North Uist, Outer Hebrides, Scotland was performed. Using fish from one of the populations with well-developed breeding coloration, experimental infections in the laboratory using a full-sib/half-sib breeding design were done. Male breeding coloration and reproductive behaviour were quantified. This dataset will give information about the evolvability of host resistance and the role of sexual selection in the evolution of host resistance. In the phase II project the emphasis will lie on the ecology of host-macroparasite interactions in this system and variation in parasite infectivity. The lakes on North Uist are of two distinguished habitat types: on the east and central parts of the island the lakes are tea-stained and acid while on the west part the lakes are clear and alkaline. Ecological influences on host-macroparasite interactions will be studied on three different levels. First, the phylogeographic dataset of sticklebacks and their Gyrodactylus and Diplostomum parasites of the phase I project will be extended and related to ecological variables like water quality (pH, visibility) and fish population size as a proxy for genetic variability. This analysis will give insights into ecological constraints on host-parasite coevolution. Second, experimental infections of lab-reared full-sib/half-sib progeny from a population with hardly developed, drab breeding coloration will, compared to similar experiments with colourful males in the phase I project, illustrate ecological constraints in the role of sexual selection in the evolution of host resistance. Third, lab-reared progeny of one of the stickleback populations will be exposed to parasites from different lochs using local, loch-specific water in order to establish interpopulational variation in parasite infectivity. This experiment will be done with Gyrodactylus and, when enough snails that shed metacercariae can be collected in the lochs, also with Diplostomum. Variation in infectivity will be related to ecological factors like water quality (pH, visibility), fish population size, and the elaboration of male breeding coloration. Together, the three different approaches will increase our understanding of the role of ecology in the evolution of host-parasite interactions.