Collaborative Research: The circadian clock's control of seasonal dormancy in mosquitoes

该研究项目的总体目标是了解生物钟调节北方家蚊（库蚊，一种传播许多疾病的蚊子）越冬休眠的分子机制。蚊子在漫长的夏季变得繁殖活跃，在短暂的冬季进入滞育或越冬休眠，此时它们不太活跃，并保存能量以在不利的环境条件下生存。生活在温带环境中的生物能够通过对日照长度或光周期的变化做出反应来预测和准备冬季的到来。昆虫如何精确地测量白昼长度尚不清楚，但提供一天中时间信息的生物钟被假设参与其中，因为它控制着植物的季节性反应。了解昆虫如何能够将环境信号（如昼长）转化为内部线索（包括基因产物和代谢产物），将有助于了解其他昆虫季节性反应的调节。这项工作有可能通过操纵季节性反应在一年中错误的时间发生来产生控制害虫的新方法，从而改善公共卫生。该项目将允许不同的研究生和本科生充分参与科学研究，并将为初中和高中学生和教师提供可访问的和引人入胜的教育计划和资源。研究人员假设，昼夜节律转录因子多效性调节昆虫的生殖和越冬途径，其方式既依赖于时钟，也依赖于日照长度。本研究的主要目的是探讨昼夜节律转录因子对北方库蚊繁殖和越冬滞育的调控机制。染色质免疫沉淀，然后深度测序（ChIP-seq）和RNA测序在时钟无效突变体背景将确定昼夜节律转录因子的目标，以及它们如何调节基因与不同的季节性反应在长和短的光周期。此外，NMR光谱将揭示与繁殖和生存相关的蚊子代谢组的每日和季节性变化。结合起来，结果将显示昆虫如何能够感知日照长度的变化，并将这些信息转化为调节不同季节反应的关键分子途径。光周期滞育在昆虫中已经进化了无数次，在那里它聚集在一些信号通路上，这些信号通路也调节其他动物的代谢和细胞周期停滞。因此，这项研究的结果将超越昆虫滞育研究，具有潜在的应用于冬眠，衰老和肥胖的研究。除了培训下一代科学研究人员外，PI还将领导昆虫学野外营地，并与K-12教师合作，开发和评估与活节肢动物，假设驱动的实验室实验，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智力价值和更广泛的影响审查标准。

The overall goal of this research project is to understand the molecular mechanisms by which the circadian clock regulates overwintering dormancy in the Northern house mosquito, Culex pipiens, a mosquito species that transmits many diseases. Mosquitoes become reproductively active during long, summer days, and enter diapause or overwintering dormancy during short, winter days, when they are less active and conserve energy to survive unfavorable environmental conditions. Organisms that live in temperate environments are able to predict and prepare for winter’s arrival by responding to changes in daylength, or photoperiod. Precisely how insects are able to measure daylength is unclear, but the circadian clock, which provides information on the time of day, is hypothesized to be involved because it controls seasonal responses in plants. Understanding how insects are able to convert environmental signals, like daylength, into internal cues, including gene products and metabolites, will provide insights into the regulation of seasonal responses in other insects. This work has the potential to generate novel ways to control insect pests by manipulating seasonal responses to occur at the wrong time of year, thereby improving public health. This project will allow diverse graduate and undergraduate students to fully participate in scientific research, and will provide accessible and engaging educational programming and resources for middle- and high-school students and teachers.The investigators hypothesize that circadian transcription factors pleiotropically regulate reproductive and overwintering pathways in both a clock- and daylength-dependent manner in insects. The overall research objective is to determine the mechanism by which circadian transcription factors regulate pathways associated with reproduction and overwintering diapause in the Northern house mosquito, Culex pipiens. Chromatin Immunoprecipitation followed by deep sequencing (ChIP-seq) and RNA sequencing in clock-null mutant backgrounds will identify the targets of circadian transcription factors and how they regulate genes associated with different seasonal responses in both long and short photoperiods. Additionally, NMR spectroscopy will reveal daily and seasonal changes in the metabolome of mosquitoes that are associated with reproduction and survival. Combined, the results will show how insects are able to perceive changes in daylength and translate this information into key molecular pathways that regulate different seasonal responses. Photoperiodic diapause has evolved numerous times among insects, where it converged on a few signaling pathways that also regulate metabolism and cell cycle arrest in other animals. Therefore, the results of this study will extend beyond insect diapause research, with potential applications to the study of hibernation, aging, and obesity. In addition to training the next generation of scientific researchers, the PIs will lead entomology field camps and work with K-12 teachers to develop and assess engaging programming with live arthropods, hypothesis-driven lab experiments, and effective educational resources that will be freely provided online.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.