Uncovering the Origin and Mechanisms of Ultradian Rhythms in the Drosophila Brain

项目总结 大脑的输入和输出都发生在广泛的时标和 在许多情况下，有节奏地重复。已经研究了基因表达的节律性变化 只有在昼夜节律的情况下才会出现在大脑中。此外，比一天更短的时间(乌拉迪安) 节律的报道很少，而且还不知道这些节律是如何起源的， 特别是在分子水平上，以及它们是否相互作用和/或共享部分 生物钟使用的计时机器。了解这些节奏是如何 产生和维护将阐明大脑基因表达和生理的新方面 并开辟了未被探索的研究领域。 为了揭示果蝇大脑中不同时间尺度的RNA振荡，我们对果蝇的大脑进行了剖析 RNAseq每两小时一次，连续三天。通过分析这些数据，我们确定了数十个 RNA在大脑中以6小时、12小时和24小时的节律振荡。有趣的是，浓缩 分析表明，超过一半的这些基因在神经胶质细胞中高度表达，这表明 这种电池的振荡器工作在不同的时间尺度上。它的重要性和新颖性 这些结果有两个方面：a.它们第一次证明了极端分子的存在。 苍蝇脑中的RNA振荡；B.表明存在运行在 神经胶质细胞中存在不同的时间尺度(昼夜节律和超长时标)。在这方面，目前 该提案旨在全面确定导致超短波的机制 苍蝇脑内神经胶质细胞的节律性基因表达。我们的工作将会揭示 首次在果蝇体内表达超广谱蛋白的新机制。此外，我们将确定 并描述了在神经胶质细胞中运行的新的计时或类似计时器的机制 有一个生物钟。最后，我们的工作将提供新的信息，并导致开发工具 在未来扰乱和研究这些节律。 总而言之，我们相信，这一项目将揭示出定时监管的新模式 大脑内的转录和生理学，这可能是非常重要的 果蝇和发现超新星和昼夜节律振荡器之间的潜在联系 在这些细胞内。这项开创性的研究将为进一步研究 脑中的一种关键细胞类型--神经胶质细胞的振荡，以及了解其机制和 超常节奏在总体上的作用。因为昼夜节律与许多疾病有关 包括抑郁症和睡眠障碍在内，目前的提案对 人类健康。

PROJECT SUMMARY Both inputs to the brain and outputs from the brain occur over a broad range of timescales and in many cases repeat rhythmically. Rhythmic changes in gene expression have been studied in the brain only in the context of circadian rhythms. Additionally, shorter-than-a-day (ultradian) rhythms have been sparsely reported and it is unknown how these rhythms originate, particularly at the molecular level and whether they interact and/or share part of the timekeeping machinery utilized by the circadian clock. Understanding how these rhythms are generated and maintained will illuminate new aspects of brain gene expression and physiology and open unexplored areas of research. In an effort to reveal RNA oscillations at different timescales in the fly brain, we profiled fly brains by RNAseq every two hours for three days. By analyzing these data, we identified dozens of RNAs oscillating with 6-, 12-, and 24-hour rhythms in the brain. Interestingly, enrichment analysis shows that more than half of these genes are highly expressed in the glia, suggesting this cell type has oscillators operating at different timescales. The importance and novelty of these results are two-fold: a. they demonstrate, for the first time, the presence of ultradian RNA oscillations in the fly brain; b. suggest the existence of oscillators operating at different timescales (circadian and ultradian) in the glial cells. In this context, the present proposal aims to comprehensively identify the mechanisms responsible for ultradian rhythmic gene expression in the glial cells within the fly brain. Our work will shed light on new mechanisms of ultradian expression in flies for the first time. In addition, we will identify and characterize new timekeeping or timer-like mechanisms operating in glial cells that also have a circadian clock. Last, our work will provide new information and lead to developing tools to perturb and investigate these rhythms in the future. In sum, we are convinced that this project will uncover new modes of timed regulation of transcription and physiology within the brain, which might be of vast importance beyond Drosophila and uncover potential connections between ultradian and circadian oscillators within these cells. This pioneering study will set the stage for further studying the role of oscillations in the glia, a key cell type in the brain, as well as to understand the mechanism and role of ultradian rhythms in general. As circadian rhythms have been linked to numerous diseases including depression and sleep disorders, the present proposal has obvious implications for human health.