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日常行为、生理和细胞代谢节律。内部时钟通过对其自身内部时钟周期进行小幅调整来与地球的 24 小时保持同步。如果生物钟被迫进行大幅调整（例如时差），则会产生负面的生理后果，因此大多数生物的生物钟与 24 小时相差不大。令人惊讶的是，一组蜘蛛物种的生物钟与 24 小时不同。 24 小时最多 5 小时，理论上来说，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。该机构项目旨在了解：(1) 蜘蛛的时钟基因和昼夜节律特性的进化变化，(2) 与 24 小时同步的限制和生理后果，以及 (3) 基本的分子发条装置总体而言，该项目将开发一个新的、独特的、强大的模型系统，以了解昼夜节律，并且从概念上讲，昼夜节律疾病对于学生来说是容易理解的，并且该项目将为阿巴拉契亚地区的本科生提供丰富的机会。参与所有三个机构的研究，该项目的社会影响将包括开发用户友好的、开放获取的应用程序以严格分析昼夜节律数据，以及年度公共宣传活动，包括自然/STEM 计划。 K-12 学生和成年人，并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，它们在物种内部和物种之间表现出广泛的内源性自由运行周期（FRP）分布。生存实验表明，平均 FRP 异常短或长（17.8-29.1 小时）的物种，与其说是遭受痛苦，不如说是通常与内源性昼夜节律周期和 24 天时间不一致相关的负面后果。通过使用综合的、多层次的方法，这些蜘蛛以某种方式摆脱了这些选择性限制，该项目将利用蜘蛛和非蜘蛛物种之间生物钟系统功能的明显进化转变来识别时钟机制的变化，从而使蜘蛛能够实现这一点。这些不寻常的蜘蛛钟的存在，利用基因组或转录组规模的数据来估计蜘蛛多样性物种八种不同时间生物学参数的进化变化率，将能够重建祖先状态并精确定位时间。比较蜘蛛类和非蜘蛛类物种的生存率将确定蜘蛛类蜘蛛是否真正摆脱了非共振光/暗循环的夹带成本，经典的相移和相位响应曲线实验将探讨蜘蛛的差异。比较蜘蛛和非蜘蛛之间的典型时钟基因表达幅度以及与已建立的昆虫模型之间的夹带潜力。将探索潜在的时钟功能差异，比较蜘蛛类动物和非蜘蛛类动物之间的时钟成分 CRY1，并将使用分子、行为和系统发育方法来测试昼夜节律系统的光敏感性差异，探讨昼夜节律的程度和功能影响。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。