Temporal Regulation of Neuronal Differentiation

描述(由申请人提供)：神经元的发展需要一个高度复杂的分化程序的展开。破译这一程序背后的调控密码与中枢神经系统疾病有直接相关性，因为许多疾病是由一个或多个神经元分化事件的中断引起的。特别是，现在清楚的是，在一些神经系统疾病中，转录因子之间的相互作用和神经元发育过程中染色质结构的动态变化发生了变化。随着神经元的成熟，它们会经历连续的成熟阶段，在这一阶段中，独特的基因亚集必须以适当的顺序和时机打开和关闭。改变这一临时计划可能会导致严重的发育缺陷。单个转录因子通常在神经元分化的多个阶段发挥作用，是什么决定了它们在不同步骤控制的不同基因亚集的时间模式尚不清楚。这项提议的中心目标是定义关键的计时机制，以确保神经元分化过程中基因转录的顺序。为了解决这个问题，我们正在探索神经元特异性基因在发育过程中的时间调节。在这项提案中，我们将检查反式激活子、反式抑制物和染色质结构之间的关键相互作用，这些相互作用共同决定涉及的转录计时器的调节。我们将研究不同的反式因子和染色质修饰物与天然染色质的时间相互作用，以及目标基因位点内发生的各种染色质修饰，包括初级神经元和中枢神经系统。启动子分析也将在原代神经元培养和体内使用转基因方法进行。此外，还将检查候选计时器的特定基因敲除，以确定反式因子干扰是否会改变体内的转录计时器。这些研究的结果将为神经元发育的不同阶段如何协调以确保适当的成熟和功能提供洞察力。他们还将确定可能导致中枢神经系统疾病的重要发育调节因子。与公共卫生相关的控制神经系统正常形成的基因缺陷经常导致严重的神经疾病。我们的研究将确定决定神经系统发育适当时机的关键机制，以及参与这一过程的候选中枢神经系统疾病相关基因。

DESCRIPTION (provided by applicant): Neuronal development requires the unfoldment of a highly complex differentiation program. Deciphering the regulatory code underlying this program has direct relevance for CNS disease, since many disorders arise from disruption of one or more neuronal differentiation events. In particular, it is now clear that the interplay between transcription factors and dynamic changes in chromatin structure during neuronal development is altered in several nervous system disorders. As neurons mature, they pass through successive maturation stages in which unique subsets of genes must be turned on and off in the proper sequence and timing. Altering this temporal program can result in serious developmental defects. Individual transcription factors often function during multiple stages of neuronal differentiation, and what determines the temporal patterning for the distinct subsets of genes they control at different steps is not understood. The central goal of this proposal is to define the critical timekeeping mechanisms that ensure the sequential ordering of gene transcription during neuronal differentiation. To address this, we are exploring the temporal regulation of a neuron-specific gene during development. In this proposal, we will examine key interactions between trans-activators, trans-repressors and chromatin structure that collaborate in determining the regulation of the transcriptional timer involved. We will examine temporal interactions of different trans-factors and chromatin modifiers with native chromatin as well as various chromatin modifications occurring within the target gene locus, both in primary neurons and within the CNS. Promoter analyses also will be performed in primary neuronal cultures and in vivo using transgenic approaches. In addition, specific gene knockouts for candidate timekeepers will be examined to determine whether trans-factor disruption alters the transcriptional timer in vivo. Results from these studies will provide insight into how different phases of neuronal development are coordinated to ensure appropriate maturation and function. They also will identify important developmental regulators that may underlie CNS disorders. PUBLIC HEALTH RELEVANCE Defects in genes that control the proper formation of the nervous system frequently giver is to severe neurological disorders. Our studies will identify key mechanisms that determine the appropriate timing of nervous system development as well as candidate CNS disease-related genes involved in this process.