Collaborative Research: Does Cytonuclear Coevolution Drive Reproductive Isolation? Dissecting the Architecture of Genetic Incompatibility Across a Species Range

自然界展示了大量的生物多样性，这些生物多样性确保了生态系统及其提供的服务的稳定性，并具有内在的审美价值。个体物种是这种生物多样性的关键要素，了解新物种是如何形成的是确保维持多样性的关键。核基因组和细胞器(线粒体和叶绿体)基因组之间的相互作用是包括呼吸和光合作用在内的关键过程的基础。这些相互作用是物种形成最早阶段的一种未被认识的、但潜在的强大推动力。这项计划中的研究将调查基因组间相互作用对物种种群间不亲和性的影响。这项研究将使用最先进的技术来确定核和细胞器基因组之间不亲和性的基因组基础，并确定这种不亲和性保持遗传差异和促进接触区物种形成的能力。该项目还将在一个以课程为基础的实验模块和研讨会中，通过实践经验和最新的基因组测序技术，向本科生以及高中和社区大学教师介绍关于物种形成和进化的核心想法。最后，该项目将提供本科生、研究生和研究生水平的培训。细胞质和核基因产品之间的相互作用有望推动基因组间的共同进化，导致具有不同细胞质基因组的群体之间可能出现遗传不亲和性和生殖隔离。虽然这种细胞核不亲和性(CNI)被认为是物种形成过程中最早形成的生殖障碍之一，但我们对CNI在物种形成早期阶段的动态仍然了解有限，特别是对于叶绿体驱动的物种形成。这项研究将研究美洲风铃中由叶绿体驱动的CNI的动态，创建一组强大的基因组资源，描述CNI遗传结构在不同谱系中的变异，并利用自然接触区来评估暴露在选择中是否改变了CNI相对于异地复交的遗传结构。总而言之，这些数据将为深入了解叶绿体-核不亲和性的进化动态以及这些动态如何推动物种形成的早期阶段提供洞察。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。

The natural world exhibits a vast array of biodiversity which ensures the stability of ecosystems, the services they provide, and has intrinsic aesthetic value. Individual species are critical elements of this biodiversity and understanding how new species form is key to ensuring maintenance of diversity. Interactions between the nuclear genome and organelle (mitochondria and chloroplast) genomes underlie key processes including respiration and photosynthesis. These interactions are an underappreciated and yet potentially powerful driver of the earliest stages of speciation. The planned research will investigate the contribution of intergenomic interactions to incompatibility between populations of a species. The research will use state-of-the art techniques to identify the genomic basis of incompatibility between the nuclear and organelle genomes and determine the ability of such incompatibility to maintain genetic divergence and facilitate speciation in a contact zone. The project will also introduce undergraduate students and high-school and community college teachers to core ideas about species formation and evolution through hands-on experience with the newest genomic sequencing technologies in a novel course-based lab module and workshop. Finally, the project will provide training at the undergraduate, graduate, and post-graduate level.Interactions between cytoplasmic and nuclear gene products are expected to drive intergenomic coevolution, leading to the potential for genetic incompatibility and reproductive isolation between populations with divergent cytoplasmic genomes. While such cytonuclear incompatibility (CNI) has been posited to be among the earliest reproductive barriers to develop during speciation, our understanding of the dynamics of CNI at the early stages of speciation remains limited, particularly for plastid-driven speciation. The research will examine the dynamics of plastid driven CNI in Campanula americana, creating a powerful set of genomic resources, characterizing variation in the genetic architecture of CNI across lineages, and leveraging a natural contact zone to evaluate whether exposure to selection alters the genetic architecture of CNI relative to allopatry. Together, these data will provide insight into the evolutionary dynamics of plastid-nuclear incompatibility and how these dynamics may drive the early stages of speciation.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.