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

进化生物学的一个主要问题是，不同种类的生物如何在长期内形成并维持互利的关系，而这些关系往往是相互冲突的。该项目将使用最先进的技术来研究昆虫农业系统，以了解肢足蚁和粉蚧之间的进化联系。顶足蚁是一种游牧蚁，它们利用粉虫的方式与人类利用牛的方式相似。蚂蚁把粉蚧放在它们的巢里，把它们放在地下植物的根上进食，然后蚂蚁以粉蚧通过专门的毛孔分泌的蜜露（液体）为食。通过重建蚂蚁和粉蚧的进化关系，我们将研究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，有助于更广泛地理解物种间相互作用的进化。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，为K-12教师提供培训，以改善K-12科学教育，并通过收集和可公开访问的网站（如AntWeb）为科学基础设施做出贡献。本研究的主要研究目标有两个：1)利用基因组水平的数据（超保守元件）对Acropyga蚁和xenococcine粉蚧虫进行系统发育研究；2)利用系统发育来检测谱系之间的共多样化。使用系统基因组学方法捕获和测序，使用下一代测序，该系统中来自两个昆虫伙伴的超保守元件将提供多个进化时间尺度的数据，从而产生强大的系统发生。粉蚧通过营养载体在蚁代之间的垂直传播，以及寄生在蚁巢中的异球菌物种的高特异性，都导致了伴侣之间共同多样化的期望。我们将检验三个假设：1)弱伴侣忠诚（null）；2)扩散感共多样化；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系统发育之间的显著共种水平。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

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.