Red Queen Dynamics in Daphnia; Revealing the Evolutionary Change in a Parasite Population

前身项目主要集中在研究宿主种群的进化变化，而在这里，我们建议调查红皇后种族的第二个参与者-寄生虫。因此，我们将筛选受感染宿主(水蚤)的野生种群。作为模型寄生虫，我们将使用原生动物Caullerya Mesnili。在前身项目中，a)我们证明了这种寄生虫可能会导致自然水蚤种群的进化变化(由于它的高毒力和强烈的感染遗传特异性)；b)我们已经发展了一种分子方法来研究Caulerya种群结构(核糖体DNA ITS区的核苷酸变异)；以及c)我们已经确定了这种寄生虫常见的几个野外地点。拟议的新研究有四个目标。我们将使用分子方法研究：1)时间变化(即在寄生虫种群内)和2)空间格局(跨种群)。重要的是，我们将使用单拷贝基因标记：延伸因子α，EF-α来验证多拷贝基因标记ITS的结果。最后，我们将寻找感染遗传特异性的分子特征。总而言之，该项目将阐明在宿主-寄生虫共同进化研究中经常被忽略的伙伴：微寄生虫的进化变化。

The precursor project has largely focused on studying evolutionary change in host populations, whereas here we propose to investigate the second player of Red Queen races – the parasites. Thus, we will screen wild populations of infected hosts (Daphnia). As the model parasite we will use the protozoan Caullerya mesnili. In the precursor project a) we showed that this parasite is likely to induce evolutionary change in natural Daphnia populations (due to its high virulence and strong genetic specificity for infection); b) we have developed a molecular approach to study Caullerya population structure (nucleotide variation in the ITS region of ribosomal DNA); and c) we have identified several field sites where this parasite is common. There are four objectives of the proposed new research. We will investigate, using molecular approaches: 1) temporal changes (i.e. within parasite populations) and 2) the spatial pattern (across populations). Importantly, 3) we will verify the results from the multi-copy gene marker ITS with a single-copy gene marker: elongation factor alpha, EF-α. Finally, we will look for 4) molecular signatures of the genetic specificity of infection. In summary, this project will shed light on evolutionary changes in otherwise often omitted partners in the host-parasite coevolutionary research: the microparasites.