DISSERTATION RESEARCH: Diversification of Spider Venoms: Patterns and Correlates of Variation within Individuals and Across Populations and Phylogenies

[9623468]麦迪逊蜘蛛毒液在捕食策略或防御中的作用在蜘蛛之间差别很大。毒液的化学成分也因蜘蛛种类而异，甚至有证据表明物种内部也存在差异。在这项研究中，我们将采用比较的方法来测试生态需求对毒液多样化的影响。我们将确定毒液存在变异的系统发育水平，然后确定毒液的变化是否在行为和生态变异的系统中更为明显。首先，我们将通过确定不同饮食对成年毒液表达的影响来分析非遗传变异。其次，我们将确定三种蜘蛛系统中低于物种水平的变异量：(1)已知种群间行为差异的Agelenopsis aperta；(2)蛇毒药理具有种群间差异的种Tegenaria agrestis；(3)生态相似但分散在不同岛屿上的夏威夷四爪龙种群。最后，我们将在物种水平上确定毒液的差异，并研究夏威夷四目龙这些变化的生态和行为相关性。夏威夷四目龙是一个经历了涉及觅食行为转变的辐射的分支。基于系统发育位置或生态环境预测毒液特征的能力，将有助于简化正在进行的具有有用生理应用的新型毒素的搜索。

9623468 Maddison The role of spider venoms in predation strategies or defense varies widely among spiders. The chemical composition of venoms also varies among spider species and there is even evidence of variation within species. In this study, we will use a comparative approach to test for the influence of ecological demands on venom diversification. We will determine phylogenetic levels at which variation in venoms exists, and then determine whether venom changes are more pronounced in systems with behavioral and ecological variability. First, we will assay nongenetic variation by determining the effect on adult venom expression that results from rearing broodmates on different diets. Second, we will determine amounts of variation below the species level in three spider systems: (1) Agelenopsis aperta, a species with known behavioral differences among populations; (2) Tegenaria agrestis, a species with evidence of interpopulational differences in venom pharmacology; and (3) populations of Hawaiian Tetragnatha that are similar ecologically but isolated on different islands. Finally, we will determine venom differences above the species level and investigate ecological and behavioral correlates of these changes in Hawaiian Tetragnatha, a clade which has undergone a radiation involving a shift in foraging behavior. The ability to predict venom characteristics, based on phylogenetic position or ecological circumstances, would help to streamline the ongoing search for novel toxins with useful physiological applications.