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

该行动资助了美国国家科学基金会2023财年生物学博士后研究奖学金，研究基因组，环境和表型之间相互作用的生命规则的综合研究。该奖学金支持将以创新方式对生活规则领域作出贡献的研究员的研究和培训。已知对地球生物多样性有贡献的一个指导性相互作用是昆虫食草动物和它们所食用的植物之间的关系。昆虫的饮食受到它们的基因、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，就会发生物种形成事件。然而，要实现这一点，必须出现新的基因。遗传变化的一个来源是杂交（即亲缘关系密切但基因不同的生物体之间的交配）。本项目旨在评估杂交对食草昆虫食性的影响。为此，评估了两种密切相关的毛虫之间的高杂交和低杂交区域。在这里，实验室和现场实验是与社区学院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，这是社区大学学生通常无法获得的。这一努力将有助于提高退伍军人在STEM领域的代表性。这项研究通过可能正在经历当代物种形成的生物之间的基因流动，探索了昆虫食草动物饮食广度进化的一个被忽视的潜在强大窗口。秋网虫是一种极端多面手的草食动物，其饮食包括600种寄主植物。秋天的网虫已经分化成两种基因上截然不同的生物类型，它们的饮食宽度也不同。尽管它们在地理上有重叠，但它们的生活史时间一直保持着生殖隔离，除了在它们的北部范围范围内出现杂交区，在那里它们的发育物候受到较短的季节窗口的限制。本项目利用生殖隔离的差异来测试杂交对饮食宽度的下游影响，方法包括：1)对跨越物候不同重叠程度的南北样带种群进行调查和基因组测序；2)基于实验室的食草动物性能分析，比较该生物型在中间寄主植物上的杂交性能；3)与老兵联合进行田间实验，评价杂交种在不同寄主群体上的捕食差异。通过探索基因流在饮食宽度进化中的作用，本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。

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.