RUI: A Phylogenomic Approach to Understanding the Symbiosis Between Acropyga Ants and Xenococcine Mealybugs

进化生物学中的一个主要问题是，不同种类的生物体如何在长期内形成并维持互利关系，通常存在相互冲突的自我利益。该项目将使用最先进的技术来研究昆虫农业系统，以了解Acropyga蚂蚁和粉蚧之间的进化联系。顶巢蚁是一种放牧蚁，它们利用粉蚧的方式与人类利用奶牛的方式类似。蚂蚁把粉蚧放在巢穴里，把它们放在地下植物的根部进食，然后蚂蚁以粉蚧通过专门的气孔分泌的蜜露（液体）为食。通过重建蚂蚁和粉蚧的进化关系，将调查这两个伙伴是否随着时间的推移影响了彼此的物种多样性。蚂蚁粉蚧系统是一个强大的模型系统，有助于更广泛地了解物种间的互惠进化。该项目还将为本科生和研究生提供分类学和系统学方面的研究培训，让K-12教师接受培训，以改善K-12科学教育，并通过收集和公开访问的网站（例如，本研究的主要研究目标是双重的：1）使用基因组学水平数据（超保守元素）进行顶蚁和异尾粉蚧的单基因组研究，以及2）使用单基因来测试谱系之间的共多样化。使用下一代测序技术，使用双基因组方法捕获和测序来自该系统中两种昆虫伴侣的超保守元件，从而产生强大的双基因组，这将提供多个进化时间尺度的数据。粉蚧的垂直传播，蚂蚁世代通过滋养和高特异性的xenococcine物种栖息在蚁巢都导致预期的合作伙伴之间的共同多样化。 我们将测试三个假设：1）弱伴侣忠诚（零）; 2）扩散意义上的共同多样化;和3）严格意义上的共同多样化。我们将利用排列和基于事件的方法来测试蚂蚁和粉蚧之间的共同物种形成的显著水平。该奖项反映了NSF的法定使命，并被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。

A major question in evolutionary biology is how different kinds of organisms can form and maintain mutually beneficial relationships over long periods of time, often with conflicting self-interests. This project will use state-of-the-art techniques to study an insect agriculture system to understand the evolutionary bonds between Acropyga ants and mealybugs. Acropyga ants are herder ants that use mealybugs in a similar way humans use diary-cattle. The ants keep the mealybugs in their nests, place them on underground plant roots to feed, and then the ants feed on honeydew (fluid) the mealybugs excrete through specialized pores. By reconstructing the evolutionary relationships of the ants and mealybugs it will be investigated whether or not the two partners have influenced each other's species diversity over time. The ant - mealybug system is a powerful model system to contribute to a broader understanding of the evolution of mutualisms among species. This project will also provide research training in taxonomy and systematics to undergraduate and graduate students, engage K-12 teachers with training to improve K-12 science education, and contribute to scientific infrastructure through collections and publicly accessible websites (e.g., AntWeb).The primary research goals of this study are twofold: 1) conduct phylogenomic studies of Acropyga ants and xenococcine mealybugs using genomics level data (ultraconserved elements) and 2) use the phylogenies to test for codiversification between lineages. The production of robust phylogenies using a phylogenomic approach to capture and sequence, using next-generation sequencing, ultraconserved elements from the two insect partners in this system will provide data at multiple evolutionary timescales. The vertical transmission of mealybugs across ant generations via trophophoresy and the high specificity of xenococcine species inhabiting ant nests both lead to the expectation of codiversification between the partners. We will test three hypotheses: 1) weak partner fidelity (null); 2) diffuse-sense codiversification; and 3) strict-sense codiversification. We will utilize both permutation and event-based methods to test for significant levels of cospeciation between ant and mealybug phylogenies.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.