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

这一行动为NSF 2023财年生物学博士后研究奖学金提供了资金，综合研究调查了支配基因组、环境和表型之间相互作用的生命规则。该奖学金支持研究员的研究和培训，这些研究员将以创新的方式为生活规则领域做出贡献。已知的有助于地球生物多样性的一个指导性相互作用是昆虫食草动物和它们所消耗的植物之间的关系。昆虫的饮食受到它们的遗传、植物的防御性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，物种形成事件就会发生。然而，要做到这一点，必须出现新的基因。基因变化的一个来源是通过杂交(即在密切相关但基因不同的生物之间交配)。该项目评估了杂交对昆虫食草动物饮食的影响。为了做到这一点，评估了两个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。这样的合作提供了社区大学学生通常无法获得的研究经验来源。这一努力将有助于促进提高退伍军人在STEM中的代表性。这项研究探索了一个被忽视的、潜在的强大窗口，通过可能正在经历当代物种形成的有机体之间的基因流动，了解昆虫食草动物的饮食广度进化。秋季网虫(Hyphantria Cunea)是一种极端的多面性食草动物，其食物包括600种寄主植物。秋季网虫已经分化成两种遗传上不同的生物型，具有不同的饮食广度。尽管有相同的地理重叠，但它们生活史的时间安排保持了生殖隔离，除了沿着它们北部活动范围的杂交区，在那里它们的发育物候受到较短的季节性窗口的限制。该项目利用生殖隔离中的变异来测试杂交对食物广度的下游影响，方法是1)对南北样带中物候重叠程度不同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分析以比较生物型中间寄主植物的杂交性能，以及3)与退伍军人合作的田间实验，以评估杂交种在不同寄主组合上的捕食差异。通过探索基因流在饮食广度进化中的作用，这项研究将有助于确定当代和未来生物多样性的维持。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势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.