NSF PRFB FY23: The role of hybridization on diet breadth evolution of a extreme dietary generalist

该行动资助了2023财年的NSF生物学博士后研究奖学金，综合研究调查了基因组，环境和表型之间的生命管理相互作用的规则。该研究金支持研究员的研究和培训，以创新的方式为生活规则领域做出贡献。一个已知的对地球生物多样性做出贡献的指导性相互作用是食草昆虫与它们所食用的植物之间的关系。昆虫的饮食受到它们的遗传、植物的防御化合物和捕食它们的昆虫捕食者之间的相互作用的限制。当这三个因素中的一个发生变化时，物种形成事件经常发生。然而，要做到这一点，必须出现新的基因。遗传变化的一个来源是通过杂交（即，密切相关但遗传上不同的生物之间的交配）。本计画评估杂交对昆虫食草性食物的影响。要做到这一点，两个密切相关的毛虫之间的高和低杂交区域进行评估。在这里，实验室和现场实验是与社区大学系统的退伍军人合作进行的。这样的合作提供了研究经验的来源，通常不提供给社区大学的学生。这一努力将有助于提高退伍军人在STEM中的代表性。这项研究探索了一个被忽视的和潜在的强大的窗口，通过可能正在经历当代物种形成的生物体之间的基因流动，昆虫食草动物的饮食宽度进化。美国白蛾（Hyphantria cunea）是一种极端的多面手食草动物，其饮食包括600种寄主植物。美国白蛾已经分化成两个遗传上不同的生物型，具有不同的食物宽度。尽管共享的地理重叠，他们的生活史的时间一直保持生殖隔离，除了一个区域的杂交发生沿着他们的北方范围的限制，在那里他们的发育物候受到较短的季节性窗口。该项目利用生殖隔离的变化来测试杂交对饮食宽度的下游影响，方法是：1）对跨越不同程度的物候重叠的南北样带中的种群进行调查和基因组测序，2）基于实验室的草食动物性能测定，以比较生物型的中间宿主植物上的杂交性能，（3）与老兵联合进行田间试验，以评估杂种对替代寄主联合的捕食差异。通过探索基因流动对饮食宽度进化的作用，这项研究将有助于确定当代和未来生物多样性的维持。该奖项反映了NSF的法定使命，并被认为值得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来支持。

This action funds an NSF Postdoctoral Research Fellowship in Biology for FY 2023, Integrative Research Investigating the Rules of Life Governing Interactions BetweenGenomes, Environment, and Phenotypes. The fellowship supports research and training of the fellow that will contribute to the area of Rules of Life in innovative ways. A guiding interaction known to contribute to Earth’s biodiversity is the relationship between insect herbivores and the plants they consume. The diet of an insect is limited by the interplay between their genetics, the plant’s defensive compounds, and the insect predators which hunt them. Speciation events often occur when one of these three factors changes. However, for this to happen, novel genes must arise. One source of genetic change is through hybridization (i.e., mating between closely related but genetically distinct organisms). This project assesses the influence of hybridization on insect herbivores’ diet. To do so, regions of high and low hybridization between two closely related caterpillars are evaluated. Here, lab and field experiments are conducted in collaboration with veterans from the community college system. Such collaborations provide sources of research experience not normally afforded to community college students. This effort will help to foster increased representation of veterans in STEM. This research explores an overlooked and potentially powerful window into diet-breadth evolution of insect herbivores via gene flow between organisms that are potentially undergoing contemporary speciation. The fall webworm (Hyphantria cunea) is an extreme generalist herbivore whose diet includes 600 hostplant species. The fall webworm has diverged into two genetically distinct biotypes with different diet-breadths. Despite sharing geographic overlap, the timing of their life histories has maintained reproductive isolation except for a zone of hybridization occurring along their northern range limits, where their developmental phenology is constrained by a shorter seasonal window. This project takes advantage of variation in reproductive isolation to test hybridization’s downstream influence on diet breadth by conducting 1) a survey and genome sequencing of populations in a north-south transect spanning different degrees of overlap in phenology, 2) lab-based herbivore performance assays to compare hybrid performance on the biotype’s intermediate host plants, and 3) field experiments in association with veterans to evaluate differences in predation of hybrids on alternative host-associations. By exploring the role of gene flow on diet-breadth evolution, this study will contribute to determining the maintenance of contemporary and future biodiversity.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.