BIOLOGICAL CLOCKS--GENES, BEHAVIOR AND NEUROBIOLOGY

生物钟——基因、行为和神经生物学

• 批准号: 6240443
• 负责人: JEFFREY C HALL
• 金额: $ 14.53万
• 依托单位: BRANDEIS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-07-01 至 1998-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6240443
• 关键词: Drosophilidae; behavioral /social science research tag; behavioral genetics; biological clocks; biological signal transduction; chimeric proteins; circadian rhythms; cyclic AMP; developmental genetics; developmental neurobiology; ethology; fusion gene; gene expression; gene mutation; genetically modified animals; immunocytochemistry; laboratory rabbit; molecular cloning; molecular genetics; neuroanatomy; neurohormones; photobiology; site directed mutagenesis

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.

昼夜节律是有机体中普遍存在的生物周期 其适当的日常调节与井密切相关 物种范围从微生物到哺乳动物。 25- 理解这些节律的遗传方法已有一年之久 最近开始揭示时钟机制的元素 是日常节奏的基础。 程序中的该子提案 项目申请围绕行为遗传、神经 昼夜节律的遗传学和分子神经生物学 果蝇。建议的实验更多地强调〜系统〜 方法而不是专注于核心的方法 分子起搏。 因此，行为的神经基础 节奏，以及后期发展的周期性特征，将是 通过节律突变体和转基因的应用进行了深入研究 携带被操纵的时钟基因形式的菌株；这些研究 包括神经元解剖输出路径的描述 是中枢神经系统起搏细胞的候选细胞，并且有选择地 这些细胞的结构和功能受到干扰 结合生物测定分子的影响 介导的神经元损伤。中央起搏器的输入路径， 引入环境线索来影响重要的日常重置 时钟，将从解剖学和元素方面进行剖析 推测参与的信号转导途径 处理重置刺激。 输出路径将是 研究了不同的生理参数 被假设为时钟的第一阶段或第二阶段目标 基因功能。 后者包括周期性变化的水平 编码的 mRNA 和蛋白质；这些分子循环将是 结合生理记录进行跟踪和 扰动，通过应用转基因，其中部分 时钟基因（称为周期）已与 DNA 序列融合 对实时报告器进行编码；这是荧光素酶活性， 最近被证明可以进行非侵入性监测 活体成年果蝇和过表达组织中的分子节律 从发育后期的动物身上移植。 遗传和 分子遗传学研究建议在两个领域进行：（1）分析 的行为和神经生物学后果 操纵时钟控制基因的表达，并影响 神经肽编码基因的相同类型的扰动 其产物与时钟基因的一个子集中共表达 CNA 起搏神经元； (2) 遗传和生物学研究 最近根据缺陷分离出节律突变体 昼夜节律行为节律：这些表观遗传学研究将 继续克隆由出现的突变定义的基因 成为颠覆重要领域的最有希望的候选人 果蝇昼夜节律系统的要素。