Circadian Clock Control of Seasonal Migration

季节性迁徙的昼夜节律时钟控制

• 批准号: 1456985
• 负责人: Christine Merlin
• 金额: $ 55.07万
• 依托单位: Texas A&M University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-05-01 至 2019-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1456985&HistoricalAwards=false
• 关键词: Circadian; Clock; Control; Seasonal; Migration

Life on earth is subjected to daily and seasonal variations in the timing of sunrise and sunset. To adapt to this rhythmic environment, animals, plants and microbes have evolved circadian clocks that orchestrate daily rhythms of physiology and behavior on a 24-hour basis. Although the role of circadian clocks in driving daily biological rhythms is relatively well known, their role in seasonal responses due to changes in day-length remain unclear. The proposed research aims to understand how animal circadian clocks in the brain regulate seasonal rhythms in behavior and physiology. The objective of this project is to determine the molecular mechanisms through which brain clocks regulate seasonal rhythms in the iconic long-distance migration of the North Eastern American monarch butterfly (Danaus plexippus). The studies will address a fundamental question in chronobiology and will advance our understanding of the molecular mechanisms underlying photoperiodic responses and migratory behavior. This could have broader implications for the conservation of endangered migratory species, and for understanding their adaptive potential to climate change. Through this project, graduate and undergraduate students will be mentored in biological clocks research and molecular genetics. Outreach activities will be conducted with local grade and high schools to introduce students to citizen science by participating in the generation of data on monarch migration patterns and the restoration of their habitat through monarch tagging programs and the creation of new Monarch Waystations. The overarching goal of the proposed research is to uncover the molecular mechanisms underlying clock-controlled seasonal rhythms in long-distance migration of the monarch butterfly. A fundamental understanding of the molecular mechanisms by which seasonal rhythms and photoperiodic responses in animals are regulated by the circadian clock has been hampered by the lack of genomic and genetic tools in non-model species (hamster, sheep, bird) that display robust photoperiodic responses, and the lack of robust photoperiodic responses in genetically tractable animals (fly, mouse). This project will take advantage of powerful molecular, genomic and genetic tools available in the monarch to (i) examine the role of circadian clocks and clock genes in the photoperiodic induction of the migratory behavioral and physiological switch, (ii), identify clock-output genes underlying the migratory switch, and (iii) disrupt candidate genes in vivo to define their impact on migratory behavior and physiology. These experiments will yield unprecedented insight into the molecular bases of insect photoperiodic responses and the genetic program underlying migratory behavior.

地球上的生命在日出和日落的时间上受到每日和季节变化的影响。为了适应这种有节奏的环境，动物、植物和微生物已经进化出昼夜节律钟，以24小时为基础协调生理和行为的日常节奏。虽然生物钟在驱动日常生物节律中的作用相对较为人所知，但由于日长的变化，它们在季节性反应中的作用仍不清楚。这项研究旨在了解动物大脑中的生物钟如何调节行为和生理的季节性节律。该项目的目标是确定大脑生物钟调节东北美洲帝王蝶（Danaus plexippus）标志性长距离迁移的季节性节律的分子机制。这些研究将解决时间生物学中的一个基本问题，并将促进我们对光周期反应和迁移行为背后的分子机制的理解。这可能对保护濒危迁徙物种以及了解它们对气候变化的适应潜力产生更广泛的影响。通过这个项目，研究生和本科生将在生物钟研究和分子遗传学指导。将与当地小学和高中开展外联活动，向学生介绍公民科学，方法是参与生成关于帝王蝶迁徙模式的数据，并通过帝王蝶标记计划和创建新的帝王蝶中转站恢复其栖息地。这项研究的总体目标是揭示帝王蝶长距离迁徙中时钟控制季节性节律的分子机制。对生物钟调控动物季节节律和光周期反应的分子机制的基本理解一直受到缺乏非模式物种（仓鼠，绵羊，鸟类）显示出强大的光周期反应的基因组和遗传工具的阻碍，以及缺乏强大的光周期反应在遗传上易处理的动物（苍蝇，小鼠）。该项目将利用强大的分子，基因组和遗传工具，在君主（i）检查昼夜节律钟和时钟基因在光周期诱导的迁移行为和生理开关的作用，（ii），确定迁移开关的时钟输出基因，（iii）破坏候选基因在体内，以确定其对迁移行为和生理的影响。这些实验将产生前所未有的洞察昆虫光周期反应的分子基础和迁移行为的遗传程序。