Molecular genetics of axon and synapse development and maintenance

项目摘要 我的研究计划的目标是阐明突触的基本机制， 轴突发育和维持。我们采取多层次的方法来研究这些过程， 主要使用C.因为这种动物模型非常适合于具有高细胞密度的体内成像， 分辨率，因为机械解剖是在生理相关的背景下， 功能性影响。我们检查了C。elegans运动回路，因为我们可以明确地 在所有发育阶段观察突触的定型模式，这是一个重要的读数， 评估突触是如何动态调节的。我们一直致力于创新 技术使轴突和突触中的细胞器和亚细胞结构可视化， 动态细胞过程的体内分析。我们是第一个看到突触重塑的人， 青少年运动电路在活的动物，其中设置了二十年的充满活力的研究，已经揭示了 协调突触连接的时间事件和空间组织的多个通路。我们 建立C。elegans轴突再生模型，并使用大规模的遗传筛选， 发现促进或抑制成年人轴突再生的基因。已经发现了许多途径 在其他动物模型中轴突再生中具有保守的作用。在这个R35应用程序中，我们将 着重于运动回路中发育性突触可塑性的机制 成熟和维持，以及成年人的神经元应激反应和轴突再生。我们 将研究神经元活动模式如何与转录调控协调， 突触和钙的体内成像与单细胞RNA测序分析在整个时期的 电路重构我们将深入了解与突触相关的分子动力学 和电路可塑性。我们对保守的MAP3K的多方面作用有着长期的兴趣 DLK蛋白，已被证明可调节从突触形成的多种细胞过程， 以及轴突再生和神经变性的重塑。我们会交叉询问 C之间的保守性。线虫和老鼠通过蛋白质产生的无膜区室 相分离现在广泛显示在组织细胞活动（包括轴突）中起关键作用 再生我们将采取整体的方法来研究蛋白质相分离， 生理相关的表达和背景，也可以模拟人类基因突变如何在人类 同系物可以改变蛋白质相分离特性。总的来说，这些发现将推动我们的 了解正常大脑功能的细胞信号网络，并提供 深入了解与突触功能障碍和轴突损伤相关的病理过程。

Project Summary The goals of my research program are to elucidate fundamental mechanisms underlying synapse and axon development and maintenance. We take multi-tiered approaches to investigate these processes, primarily using C. elegans because this animal model is well suited for in vivo imaging with high cellular resolution and because mechanistic dissection is within physiological relevant contexts and coupled with functional impacts. We examine the C. elegans locomotor circuit, because we can unambiguously observe the stereotyped patterns of synapses in all developmental stages, an essential readout to assess how synapses are dynamically regulated. We have consistently developed innovative technologies enabling visualization of organelles and subcellular structures in axons and synapses for in vivo analyses of dynamic cellular processes. We were the first to visualize synapse remodeling of juvenile motor circuit in living animals, which set two decades of vibrant research that have revealed multiple pathways coordinating temporal events and spatial organization of synaptic connections. We established C. elegans axon regeneration model, and have used large-scale genetic screens to discover genes that promote or repress axon regrowth in adults. Many pathways have been found to have conserved roles in axon regeneration in other animal models. In this R35 application, we will focus on mechanisms underlying both the developmental synapse plasticity in locomotor circuit maturation and maintenance, and also neuronal stress response and axon regeneration in adults. We will investigate how neuronal activity pattern coordinates with transcriptional regulation by combining in vivo imaging of synapse and calcium with single-cell RNA sequencing analysis over the entire period of circuit remodeling. We will gain a deep understanding of molecular dynamics associated with synapse and circuit plasticity. We have long-standing interest in the multifaceted roles of the conserved MAP3K DLK proteins, which have been shown to regulate diverse cellular processes from synapse formation and remodeling to axon regeneration and neurodegeneration. We will cross-examine mechanistic conservation between C. elegans and mice. Membraneless compartments generated through protein phase separation are now widely shown to play key roles in organizing cellular activities, including axon regeneration. We will take a holistic approach to investigate protein phase separation with physiological relevant expression and contexts, and also to model how genetic mutations in human homologs may alter protein phase separation properties. Overall, the findings will advance our knowledge on the cellular signaling network underlying normal brain function and will also provide insights into pathological processes associated with synapse dysfunction and axonal damage.