Defining the role of Tox3 in congenital cerebellar hypoplasia and ataxia

项目总结/摘要 小脑是一个精致的层状结构，调节平衡、自主运动协调和 通过与前脑的连接来调节语言和认知。就在前脑下面， 据估计，小脑包含了人类大脑中大约80%的神经元。因此，小脑 发育不全、病理学或功能障碍与许多疾病或病症有关，包括共济失调， 自闭症和智力缺陷大多数小脑神经元是一种称为小脑颗粒细胞（CGC）的亚型， 它是从一个称为菱形唇（RL）的结构胚胎产生的-一个位于 第四脑室室带与顶板的交界面。机制导致 对RL生殖龛的特化和随后的颗粒细胞世代保持不完全 明白具体来说，表观遗传学和转录组学的变化是心室区 前体细胞选择成为RL在很大程度上是未知的。我们创造了一个新的条件 Tox 3基因敲除（cKO）小鼠，Tox 3是TOX家族转录因子的一个成员， 与T细胞中表观遗传学的调节有关。在RL规范之前丢失TOX 3导致几乎完全 CGC发育不全和100%的渗透性共济失调。我们假设TOX 3介导了一个表观遗传开关， 从菱形唇产生小脑颗粒细胞前体所必需的， 心室区-其丧失导致发育性共济失调。利用我们成熟的生物信息学 管道和单细胞方法结合小鼠和人类模型系统，我们将 拟研究Tox 3调控小脑组织发生的机制。 我们建议分两部分进行这项工作。具体目标1的重点是询问表观遗传 使用多模式单细胞RNA和ATAC测序的Tox 3 cKO的转录组学结果 结合单细胞Cut&Tag来确定调节VZ/RL前体和CGC的遗传网络 创世纪Specific Aim 2的主要目标是使用以下方法来确定TOX 3在小鼠小脑谱系中的作用： 诱导型Cre驱动子和体细胞诱变。

PROJECT SUMMARY / ABSTRACT The cerebellum is an exquisitely laminated structure regulating the balance, voluntary motor coordination and modulating language and cognition through connections with the forebrain. Sitting just under the forebrain, cerebellum is estimated to contain roughly 80% of the neurons in the human brain. Accordingly, cerebellar dysgenesis, pathology, or dysfunction is associated with a host of diseases or disorders, including ataxia, autism, and intellectual deficit. Most cerebellar neurons are a subtype called cerebellar granule cells (CGCs), which are generated embryonically from a structure termed the rhombic lip (RL)—a germinal zone residing at the interface between the ventricular zone (VZ) and roof plate of the fourth ventricle. The mechanisms leading to the specification of the RL germinal niche and subsequent generation of granule cells remain incompletely understood. Specifically, the epigenetic and transcriptomic changes underlying how the ventricular zone precursor cells choose the to become RL are largely unknown. We have generated a novel conditional knockout (cKO) mouse for Tox3, a member of the TOX family of transcription factors previously associated with the regulation of epigenetics in T Cells. Loss of TOX3 prior to RL specification leads to almost complete agenesis of CGCs and 100% penetrant ataxia. We hypothesize that TOX3 mediates an epigenetic switch necessary for the generation of cerebellar granule cell precursors from the rhombic lip and associated ventricular zone—the loss of which results in developmental ataxia. Using our mature bioinformatics pipelines and single-cell approaches in combination with both mouse and human models systems, we will propose to investigate the mechanisms by which Tox3 regulates cerebellar histogenesis. We propose to carry out this work in two parts. The focus of Specific Aim 1 is to interrogate the epigenetic and transcriptomic consequences of cKO of Tox3 using multimodal single-cell RNA- and ATAC-sequencing combined with single-cell Cut&Tag to determine genetic networks regulating VZ/RL precursors and CGC genesis. The main goal of Specific Aim 2 is to define the role of TOX3 on murine cerebellar lineages using inducible Cre drivers and somatic mutagenesis.