Collaborative Research: RUI: Extraordinary circadian clocks in araneoid spiders: an integrative approach to understanding their evolutionary origins and underlying mechanisms

合作研究：RUI：类蜘蛛的非凡生物钟：一种理解其进化起源和潜在机制的综合方法

• 批准号: 2235710
• 负责人: Darrell Moore
• 金额: $ 40.36万
• 依托单位: East Tennessee State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-06-01 至 2026-05-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2235710&HistoricalAwards=false
• 关键词: Collaborative; Research; RUI; Extraordinary; circadian

Circadian rhythms are daily rhythms of behavior, physiology, and cellular metabolism that are driven by molecular cycles of an internal biological clock. Internal clocks remain in sync with the earth’s 24-h day by making small adjustments to their own internal clock period. However, there are negative physiological consequences if the clock is forced to make large adjustments (e.g., jetlag) so most organisms’ clocks do not vary much from 24 hours. Surprisingly, a group of spider species possess clocks that differ from 24 hours by as much as 5 hours with no apparent consequences. In theory, these species should not exist. However, the spider system provides a unique opportunity to explore basic mechanisms of circadian clocks, particularly how organisms synchronize with their environment. This multi-institutional project is designed to understand: (1) the evolutionary changes in clock genes and circadian properties in spiders, (2) the limits and physiological consequences of synchronizing to the 24-h day, and (3) the fundamental molecular clockworks of spiders. Overall, this project will develop a new, and uniquely powerful, model system to understand circadian rhythms and, potentially, circadian illnesses. Circadian rhythms are conceptually accessible to students and this project will support rich opportunities for undergraduates in the Appalachian region to participate in research at all three institutions. Societal impacts of this project will include development of user-friendly, open-access applications for rigorous analyses of circadian data, annual public outreach events including nature/STEM programs for K-12 students as well as adults, and conducting original experiments in local high schools. Araneoid spider circadian rhythms are unlike most others found on Earth. They exhibit remarkably broad distributions of endogenous free-running periods (FRPs) both within and among species, including species with exceptionally short or long mean FRPs (17.8-29.1 hours). Rather than suffering negative consequences typically associated with dissonance between endogenous circadian period and the 24-hour day, survivorship experiments suggest that these spiders are somehow released from these selective constraints. Using an integrative, multi-level approach, this project will exploit the apparent evolutionary shift in circadian clock system function between araneoid and non-araneoid spider species to identify changes in the clock mechanisms that enable these unusual araneoid clocks to exist. Using genomic or transcriptomic-scale data to estimate rates of evolutionary change in eight different chronobiological parameters for species spanning the diversity of spiders will enable reconstruction of ancestral states and pinpoint the timing of evolutionary shifts. Comparing survivorship among araneoid and non-araneoid species will determine if araneoid spiders truly have been released from the costs of entrainment to non-resonant light/dark cycles. Classic phase-shifting and phase-response curve experiments will probe differences in entrainment potential between araneoid and non-araneoid spiders. Comparing canonical clock gene expression amplitudes between araneoid and non-araneoid spiders and to established insect models will explore potential clock function differences. Comparing the functionality of the clock component CRY1 between araneoid and non-araneoid species will test for differences in light sensitivity of the circadian system. Using molecular, behavioral, and phylogenetic approaches, this project explores the extent and functional ramifications of circadian plasticity in wild clocks.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.

昼夜节律是由内部生物钟的分子周期驱动的行为、生理和细胞代谢的日常节律。内部时钟通过对自己的内部时钟周期进行微调，保持与地球24小时的同步。然而，如果生物钟被迫做出大的调整（例如，时差），那么大多数生物体的生物钟与24小时相差不大，就会产生负面的生理后果。令人惊讶的是，一组蜘蛛物种的生物钟与24小时相差多达5个小时，而没有明显的后果。理论上，这些物种不应该存在。然而，蜘蛛系统提供了一个独特的机会来探索生物钟的基本机制，特别是生物体如何与环境同步。这个多机构合作的项目旨在了解：(1)蜘蛛生物钟基因的进化变化和昼夜节律特性；(2)与24小时同步的限制和生理后果；(3)蜘蛛的基本分子生物钟。总的来说，这个项目将开发一个新的、独特的、强大的模型系统来理解昼夜节律和潜在的昼夜节律疾病。学生可以从概念上理解昼夜节律，该项目将为阿巴拉契亚地区的本科生提供丰富的机会，让他们参与这三家机构的研究。该项目的社会影响将包括开发用户友好的开放获取应用程序，用于严格分析昼夜节律数据，为K-12学生和成人提供年度公共推广活动，包括自然/STEM项目，以及在当地高中进行原创实验。蜘蛛的昼夜节律与地球上发现的大多数其他蜘蛛不同。它们的内源自由运行周期（FRPs）在种内和种间分布非常广泛，包括平均FRPs特别短或特别长（17.8 ~ 29.1小时）的物种。生存实验表明，这些蜘蛛在某种程度上从这些选择性约束中解脱出来，而不是遭受内源性昼夜节律周期和24小时工作日之间不协调的负面后果。该项目将采用一种综合的、多层次的方法，利用蛛形和非蛛形蜘蛛物种之间生物钟系统功能的明显进化转变，以确定使这些不寻常的蛛形时钟存在的时钟机制的变化。利用基因组或转录组尺度的数据来估计跨越蜘蛛多样性的物种的8种不同时间生物学参数的进化变化率，将有助于重建祖先状态并精确确定进化转变的时间。比较蛛形纲和非蛛形纲物种的存活率将决定蛛形纲蜘蛛是否真的已经从非共振光/暗周期的束缚中解脱出来。经典的相移和相响应曲线实验将探讨蛛形蜘蛛和非蛛形蜘蛛在引诱电位方面的差异。比较类蜘蛛和非类蜘蛛以及已建立的昆虫模型之间的标准时钟基因表达幅度将探索潜在的时钟功能差异。比较类蜘蛛和非类蜘蛛物种之间的生物钟成分CRY1的功能将测试昼夜节律系统的光敏性差异。利用分子、行为和系统发育的方法，该项目探索了野生时钟中昼夜节律可塑性的程度和功能分支。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。