Collaborative Research: Evolution of adaptive synergism between mutualistic partners during range-limit evolution

本研究将阐明相互作用物种的生态和进化过程如何在其范围内对气候变化作出反应，对边缘生境物种的保护具有重要意义。气候变化改变了物种分布，对嵌入复杂生态相互作用中的物种产生重大影响，例如共生共生（例如，植物-传粉者或宿主-微生物的共生关系）。这个项目的重点是昆虫-真菌的共生关系，切叶蚁培育真菌作为食物，这是美国西南部和整个新大陆的农业害虫。由于切叶蚁是生态系统的主要组成部分，而且实验抗真菌组合可以在实验室条件下模拟气候变化下预期的温度压力变化，因此切叶蚁共生是研究共生如何应对气候变化的理想选择。本研究采用了用于研究生物体内基因间相互作用的技术，以测试蚂蚁与真菌的协同作用是否增强了温度胁迫适应性，从而确定了切叶蚁在北部（美国）和南部（乌拉圭/阿根廷）的分布界限。提高对相互作用物种如何应对气候变化的认识具有科学和社会效益，有助于开发边缘生境物种保护模型，以及预测气候变化下共生有害物种是否会变得更有问题的模型。与乌拉圭和阿根廷科学家的合作将在国际环境下为美国科学家提供培训。该项目是一个大型研究机构、一个区域机构和一个为代表性不足的学生服务的机构之间的合作，其中一些实地研究将进行，并将加强长期互动，并有助于促进STEM教育的发展。此外，与乌拉圭和阿根廷科学家的合作将在国际环境下为美国科学家提供培训。讲习班将在公立学校、博物馆和自然中心举办，以促进对当地生物多样性、保护和环境变化下的挑战的理解。

This research will elucidate how the ecological and evolutionary processes of interacting species will respond to climate change at their range limits, with implications for conservation of species in marginal habitat. Climate change alters species distributions, with major consequences for species embedded in complex ecological interactions, such as mutualistic symbioses (e.g., plant-pollinator or host-microbe mutualisms). This project focuses on an insect-fungus mutualism, leafcutter ants cultivating fungi for food, which are agricultural pests in the southwestern USA and throughout the New World. Leafcutter mutualisms are ideal to study how symbioses respond to climate change because leafcutter ants are dominant components in ecosystems, and because experimental ant-fungus combinations can be manipulated under laboratory conditions simulating the altered temperature stresses expected under climate change. This research adapts techniques developed for the study of gene-by-gene interactions within an organism to test whether ant-by-fungus synergy enhances temperature-stress adaptations and thus determines range-limits at the northern (USA) and southern (Uruguay/Argentina) distributional limits of leafcutter ants. Improved understanding of how interacting species respond to climate change has scientific and societal benefits, contributing to development of models for conservation of species in marginal habitat, and to models predicting whether mutualistic pest species may become more problematic under climate change. Collaborations with researchers in Uruguay and Argentina will provide training of US researchers in an international setting. This project is a collaboration among a major research institution, a regional institution, and an institution serving underrepresented students where some of the field research will be conducted, and will strengthen long term interactions and help foster enhanced STEM education initiatives. Furthermore, collaborations with researchers in Uruguay and Argentina will provide training of US researchers in an international setting. Workshops will be conducted at public schools, museums, and nature centers to foster understanding of local biodiversity, conservation, and challenges under environmental change.