MCA: Neurogenetic divergence during incipient speciation in chorus frogs

物种间的相互作用可以间接地促进新物种的进化，特别是当一个群落中的物种组合在不同的地理位置时。当不同物种试图杂交时，由此产生的后代可能适合度较低。昂贵的杂交不仅会导致物种间的交配行为的差异，也会导致同一物种的种群之间的交配行为的差异，从而导致新物种的起源。这个项目的目的是了解青蛙大脑中的听觉神经元是如何随着物种形成过程中不同种群之间的声音交配行为的差异而进化的。这项工作将通过将先前的实地研究与新的听觉神经元实验相结合来完成。这些研究将促进对声音(例如，节拍、节奏)中包含的基于时间的信息在大脑中如何解释，以及信号中的时序差异如何影响行为反应的理解。这项研究将为新物种如何形成提供前所未有的洞察力，从生物体和种群水平到单个神经元和基因组水平。该项目将为首席研究员和一名研究生提供培训和保护时间，让他们在生物学多个分支的交叉点从事前沿研究。此外，这项工作将通过产生综合的数据集、例子和多媒体材料来加强正在进行的推广活动，以吸引学生探索引人注目的生物学问题。该项目将把促进物种形成的广泛进化过程与有助于生殖隔离的中枢神经系统的细微变化联系起来。将对合唱青蛙(伪蛙)进行研究，这是一个经历级联强化的系统-通过物种之间的相互作用间接导致物种内的行为分歧。该项目将通过对听觉中脑神经元的神经生理学实验，确定物种种群之间基于时间间隔的交配偏好的神经关联。具体地说，这项工作将测试两种发散机制：神经调谐的重新缩放和听觉神经元类别之间的重新分配。这项研究还将在单核水平上测试亲离子受体基因和其他参与行为分化青蛙种群之间突触传递的基因的差异表达。特别是，这项工作将确定候选突触传递基因的表达是否与行为进化相关。这项计划中的研究将开辟新的研究途径，为跨越神经科学、行为生态学、基因组学和进化生物学的综合研究提供一个跳板。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。

Species interactions can indirectly promote the evolution of new species, particularly when the combination of species within a community varies across geography. When different species attempt to hybridize, the resulting offspring may have low fitness. Costly hybridization can not only cause divergence of mating behaviors between species but also among populations of the same species, leading to the origin of new species. The purpose of this project is to understand how auditory neurons in the frog brain evolve as acoustic mating behaviors diverge among populations during speciation. This work will be accomplished by integrating prior field studies with new experiments on auditory neurons. These studies will advance understanding of how the time-based information contained in sounds (e.g., beats, rhythms) is interpreted in the brain and how the timing differences in signals affect behavioral responses. The research will offer unprecedented insight into how new species form, from the level of organisms and populations to the single neuron and genomic levels. The project will provide training and protected time for the lead researcher and a graduate student to engage in cutting-edge research at the intersection of multiple branches of biology. Furthermore, the work will enhance ongoing outreach activities by generating integrative data sets, examples, and multimedia materials to engage students in the exploration of compelling biological questions.This project will connect broad-scale evolutionary processes promoting speciation to fine-scale changes in the central nervous system that contribute to reproductive isolation. Research will be conducted on chorus frogs (Pseudacris), a system undergoing cascade reinforcement—a process through which interactions between species indirectly cause behavioral divergence within species. This project will identify neural correlates of time interval-based mating preferences across speciating populations through neurophysiological experiments on neurons of the auditory midbrain. Specifically, this work will test two mechanisms of divergence: rescaling of neural tuning and redistribution between auditory neuron classes. The study will also test for differential expression of ionotropic receptor genes and other genes involved in synaptic transmission between behaviorally-divergent frog populations at the single-nuclei level. In particular, this work will determine whether expression of candidate synaptic transmission genes is correlated with behavioral evolution. The planned research will open new avenues for inquiry, providing a launching pad for integrative studies spanning neuroscience, behavioral ecology, genomics, and evolutionary biology.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.