BIOLOGICAL CLOCKS--GENES, BEHAVIOR AND NEUROBIOLOGY

昼夜节律是生物体中普遍存在的生物周期 其合理的日常调节与油井密切相关 属于从微生物到哺乳动物的各种物种。这25个- 一年来，用遗传学的方法来理解这些节奏 最近开始揭示时钟机制的元素， 这是日常节奏感的基础。计划中的此子建议 项目申请围绕着行为遗传学、神经- 昼夜节律的遗传学和分子神经生物学 果蝇。实验建议强调更多的a~系统~ 而不是一种专注于 分子起搏。因此，行为的神经基础 节奏，以及后期发展的一个周期性特征，将是 节律突变体和转基因的应用研究 携带操纵型时钟基因的菌株；这些研究 包括对来自神经元解剖输出路径的描述 它们是中枢神经系统起搏细胞的候选细胞，并选择性地 对这类细胞的结构和功能的影响 结合生物测定分子的影响 介导性神经元损伤。到中央起搏器的输入路径， 它们带来了环境线索，以影响关键的每日重新设置 时钟，将从解剖学和元素两个方面进行解剖 一系列可能参与的信号转导通路 对重置刺激进行处理。输出路径将是 针对不同的生理参数进行研究， 假设是时钟的第一阶段或第二阶段目标- 基因的功能。后者包括周期性变化的 编码的mRNA和蛋白质；这些分子循环将是 结合生理记录和 扰动，通过应用转基因，在其中一部分 时钟基因(称为PERIOD)已与DNA序列融合 编码实时报告；这是荧光素酶活性，作为 最近被证明允许非侵入式监测 成虫活组织和Per表达组织中的分子节律 从发育后期的动物身上解释出来的。遗传和 分子遗传学研究主要集中在两个方面：(1)分析 的行为和神经生物学后果 操纵钟控基因~S的表达，并影响 神经肽编码基因的同种扰动 其产物与时钟基因在 (2)CNA起搏神经元的遗传学和生物学研究 节律突变体，最近分离出来的基础上的缺陷 昼夜行为节律：这些表观发生研究将 继续克隆由出现的突变定义的基因 成为最有希望颠覆重要的 果蝇的组成要素~S昼夜节律系统。

Circadian rhythms are organismically ubiquitous biological cycles whose propr daily regulation is strongly connected to the well being of species ranging from microbes to mammals. The 25- year-old genetic approach toward understanding these rhythms has recently begun to reveal elements of the clock mechanisms that underlie daily rhythmicities. This sub-proposal in a Program Project application revolves around the behavioral genetic, neuro- genetics, and molecular neurobiology of circadian rhythms in Drosophila. The experiments proposed stress more of a ~systems~ approach than one that would concentrate upon the hard core of molecular pacemaking. Thus, the neural substrates of behavioral rhythms, and a periodic feature of late development, will be delved into by application of rhythm mutants and transgenic strains carrying manipulated forms of clock-genes; these studies include descriptions of anatomic output pathways from neurons that are candidate for CNS-pacemaker cells, and selectively effected perturbations of the structure and function of such cells in conjunction with bioassaying the effects of the molecularly mediated neuronal damage. Input paths to the central pacemakers, which bring in environmental cues to effect crucial daily re-sets of the clock, will be dissected both in terms of anatomy and elements of signal-transduction pathways that putatively participate in processing the resetting stimuli. Output pathways will be investigated, with respect to varying physiological parameters that are hypothesize to be the first- or second-stage targets of clock- gene functions. The latter includes cyclically varying levels of the encoded mRNAs and proteins; these molecular cyclings will be tracked in conjunction with physiological recordings and perturbations, by applying a transgene in which portions of a clock gene (called period) have been fused to DNA sequences encoding a real-time reporter; this is luciferase activity, which as recently been shown to permit non-invasive monitoring of molecular rhythms in live adult flies and in per-expressing tissues explanted from animals late in development. Genetic and molecular-genetic studies are proposed in two areas: (1) analysis of the behavioral and neurobiological consequences of manipulating a clock-controlled gene~s expression, and of effecting the same kinds of perturbations of a neuropeptide-encoding gene whose product is co-expressed with clock genes in a subset of the CNA pacemaking neurons; (2) genetic and biological studies of rhythm mutants, recently isolated on the basis of defects in circadian behavioral rhythms: these phenogenetic studies will proceed into cloning of the genes defined by mutations that appear to be the most promising candidates for disrupting important elements of Drosophila~s circadian system.