RNA regulatory networks in neuronal cell type diversity and function

项目总结 神经细胞类型多样性和功能中的RNA调控网络 哺乳动物的大脑可能是人体中最复杂的器官，其正常的功能需要 许多不同类型的兴奋性和抑制性神经元的协调，形成不同的功能回路。 对神经细胞类型的表征不仅是了解大脑如何工作的基础，也是了解大脑如何工作的基础 特定的细胞类型在多种神经元疾病中受到选择性的影响，以及这一过程如何被逆转。 最近根据大量的基因表达谱定义了大量的神经细胞类型 单个细胞，并且这些细胞类型被组织成分层的细胞分类。可选剪接是一种 产生具有不同功能的多种转录本和蛋白质变体的机制，从而提供了一种主要的 哺乳动物分子多样性的驱动力。我的研究小组的首要目标是了解 大脑中选择性剪接和潜在的RNA调控网络的作用以及脑相关 精神错乱。包括我们在内的多个研究小组之前的研究明确表明，大脑具有 与非神经性组织相比，独特的剪接调节程序。我们的研究还揭示了 多个RNA结合蛋白(RBPs)调控的泛神经元剪接程序的建立 并证明了RBFox蛋白家族在调节轴突中的重要作用 成熟度和神经元兴奋性。然而，选择性剪接如何有助于不同的分子 大脑皮层中不同类型神经细胞的轮廓目前还知之甚少。我们假设 由高度调控的可选外显子产生的转录组多样性是指定 神经细胞类型的识别和功能。在这个应用中，我们描述了我们对神经细胞的初步分析 小鼠大脑皮质中特定类型的选择性剪接调节，这为以下方面提供了强有力的支持 我们希望追求的具体目标：1)对神经元类型特定的替代方案进行系统分析 使用深层sc-rna-seq数据进行剪接以识别新的神经元亚类和调节子。2)验证我们的 神经细胞类型特异性剪接调控和调控机制的计算预测和表征 使用两个互补模型系统的函数：GABA能的两个主要子类的区别 起源于尾侧(CGE)和内侧(MGE)神经节隆起的中间神经元和GABA能神经元- 为了实现我们的目标，我们将使用多学科方法， 将尖端的统计和机器学习方法与多种体外和体内实验相结合 模特们。这项研究将在全球范围内对精确的选择性剪接监管产生机械观点 不同的神经细胞类型，并说明其对神经元结构和功能特性的影响。

PROJECT SUMMARY RNA regulatory networks in neuronal cell type diversity and function The mammalian brain is probably the most complex organ in the body and its proper function requires coordination of many diverse types of excitatory and inhibitory neurons that form distinct functional circuitries. Characterization of neuronal cell types is fundamental to understand not only how the brain works, but also how specific cell types are selectively affected in multiple neuronal disorders and how this process can be reversed. A large number of neuronal cell types were recently defined based on their gene expression profiles in bulk and single cells, and these cell types are organized into a hierarchical cell taxonomy. Alternative splicing is a mechanism to generate multiple transcript and protein variants with distinct functions, thus providing a major driving force of the molecular diversity in mammals. The overarching goal of my research group is to understand the contribution of alternative splicing and the underlying RNA-regulatory networks in the brain and brain-related disorders. Previous work from multiple groups, including ours, unambiguously demonstrated that the brain has unique splicing-regulatory programs compared to non-neuronal tissues. Our studies also revealed the establishment of a pan-neuronal splicing program regulated by multiple RNA-binding proteins (RBPs) during neural development, and demonstrated the important role of the Rbfox protein family in regulating axonal maturation and neuronal excitability. However, how alternative splicing contributes to the distinct molecular profiles of diverse neuronal cell types in the cortex is currently poorly understood. We hypothesize that the transcriptome diversity generated by highly regulated alternative exons is a major component that specifies neuronal cell type identity and function. In this application, we describe our preliminary analysis of neuronal cell type-specific alternative splicing regulation in mouse cortex, which provides strong support for the following specific aims we would like to pursue: 1) Perform systematic analysis of neuronal cell type-specific alternative splicing to identify novel neuronal subclasses and regulators using deep sc-RNA-seq data. 2) Validate our computational predictions and characterize mechanisms of neuronal cell type-specific splicing regulation and function using two complementary model systems: the distinction of two major subclasses of GABAergic interneurons originating from caudal (CGE) and medial (MGE) ganglionic eminences, and a GABAergic neuron- specific microexon in Ank3/Ankyrin G. To achieve our goal, we will use a multidisciplinary approach that integrates cutting-edge statistical an machine learning methods and multiple in vitro and in vivo experimental models. This study will generate a global and mechanistic view of precise alternative splicing regulation across diverse neuronal cell types and illuminate its impact on neuronal structural and functional properties.