Roles of Chromatin Regulation in Specification of Neuronal Cell Identity

一个特定的细胞如何发育成最终的细胞类型是发育生物学中一个长期存在的问题。我的研究项目检查了神经元基因表达程序中染色质调节的机制，以及染色质结构如何影响指定神经元细胞身份的转录。在接下来的5年里，我的实验室将致力于以下三个研究目标：1)确定影响基因表达的染色质结构，以确定神经细胞的身份；2)全面表征神经元特异的染色质调节机制；3)研究胚胎发育过程中转录机制的染色质相互作用。为了实现目标1，我们将研究运动神经元分化过程中转录因子结合部位周围的染色质组织。我们将使用小鼠胚胎干细胞培养和转基因小鼠模型系统，结合各种基因组方法来确定神经元特异性基因表达计划的基因组要求。这些方法将揭示神经转录因子在胚胎发育过程中对染色质结构的影响。在目标2中，我们将进行两个项目，研究染色质调节蛋白如何以细胞类型特异性的方式控制染色质组织。首先，我们将使用CRISPR/Cas9基因组编辑系统识别神经元特异性染色质重塑因子。其次，我们将研究染色质重塑因子通过与神经元转录因子相互作用而被招募到靶基因的机制。在目标3中，我们将研究顺式调节元件如何通过染色质环相互作用。在一个项目中，我们将开发一种新的基因组图谱方法来检测特定基因的增强子和核心启动子之间的染色质相互作用。在第二个项目中，我们将测试转录因子在小鼠胚胎干细胞分化过程中如何在基因表达的远程控制中发挥作用。影响和培训：这些目标的结果将提供对转录和染色质调节蛋白在神经元基因表达计划过程中的机制和功能的全面理解。我们的成果将为广大研究界提供新的见解、新的方法和宝贵的资源，从而为科学的进步做出贡献。高素质的人员(HQP)将在我的实验室开展研究中发挥关键作用。在5年的资助期内，我将培训所有级别的15名HQP(博士、硕士、理科)。我的新研究计划的目标将为HQP提供在干细胞、神经生物学和基因组学领域获得高度期望的技能的重要机会。拟议的研究计划将为HQP在未来的科学事业中取得成功做好充分的准备。

How a particular cell develops into a final cell type is a long-standing question in developmental biology. My research program examines the mechanisms of chromatin regulation in neuronal gene expression programs, and how chromatin architecture impacts transcription in specification of neuronal cell identity. In the next 5 years, my lab will address the following three research objectives.1) Determine the chromatin structure affecting the gene expression to specify neuronal cell identity.2) Comprehensively characterize the mechanisms of neuron-specific chromatin regulation.3) Examine long-range chromatin interactions of transcription machinery during embryonic development.To achieve Objective 1, we will examine chromatin organization around the transcription factor-binding sites during motor neuron differentiation. We will use mouse embryonic stem cell culture and transgenic mouse model systems, combined with various genomic methods to determine the genomic requirements of neuron-specific gene expression programs. These approaches will reveal the impact of the neuronal transcription factors on chromatin structure during embryonic development.In Objective 2, we will conduct two projects that examine how chromatin regulatory proteins control chromatin organization in a cell type-specific manner. First, we will identify neuron-specific chromatin remodelling factors using the CRISPR/Cas9 genome editing system. Second, we will investigate the mechanisms by which chromatin remodelling factors are recruited to target genes by interacting with the neuronal transcription factors.In Objective 3, we will examine how cis-regulatory elements interact with one another by chromatin looping. In one project, we will develop a new genomic mapping method to detect chromatin interactions between enhancers and core promoters of a particular gene. In a second project, we will test how transcription factors play roles in the long-range control of gene expression during mouse embryonic stem cell differentiation. Impact and Training: The results from these objectives will provide a comprehensive understanding of the mechanisms and functions of transcriptional and chromatin regulatory proteins in the process of neuronal gene expression programs. Our results will contribute to the advancement of science by providing new insights, new methodologies, and valuable resources to the broad research community.Highly qualified personnel (HQP) will play an essential role in conducting the research in my laboratory. Over the 5-year funding period, I will train 15 HQP at all levels (PhD, MSc, BSc). The objectives of my novel research program will provide significant opportunities for HQP to gain highly desired skills in the areas of stem cell, neurobiology, and genomics. The proposed research program will adequately prepare HQP to move on to successful future careers in science.