Understanding CTCF boundaries controlling Hox gene expression

了解控制 Hox 基因表达的 CTCF 边界

• 批准号: 10116495
• 负责人: Esteban Orlando Mazzoni
• 金额: $ 46.8万
• 依托单位: NEW YORK UNIVERSITY SCHOOL OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-03-15 至 2023-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10116495
• 关键词: 3-Dimensional; Affect; Binding; Body Patterning; Cell Differentiation process; Cells; Chromatin; Chromatin Structure; Chromosome Structures; Complement; Development; Developmental Biology; Embryonic Development; Enhancers; Ensure; Gene Activation; Gene Expression; Gene Expression Regulation; Genes; Genome; Genomics; Homeobox Genes; In Vitro; Individual; Inherited; Light; Mediating; Molecular; Motor Neurons; Mus; Nucleic Acid Regulatory Sequences; Organism; Pattern; Positioning Attribute; Proteins; Proteomics; Published Comment; RNA; Regulator Genes; Site; Spinal; Spinal Cord; System; Transcription Initiation Site; Transcriptional Regulation; cohesin; experience; experimental study; functional genomics; in vivo; interest; loss of function; motor control; mutant; novel; transcription factor

Understanding CTCF boundaries controlling Hox gene expression Summary Spatial and temporal control of gene expression is crucial for the development of multicellular organisms. Although changes in looping interactions between enhancers and transcription start sites is an acknowledged mode of gene regulation, the contribution of larger 3D genomic reorganizations to gene expression and normal development is largely obscure. We propose experiments to clarify how the CTCF transcription factor controls chromatin structure at the Hox clusters to ensure proper Hox gene expression and thus, body patterning. During embryonic development, precise expression of Hox genes instructs cells to recognize their relative position in body axes. Hox genes are organized in four clusters with individual genes in these clusters expressed in patterns that are spatially and temporally collinear with their physical chromosomal organization. Collinear Hox gene expression along the spinal cord controls motor neuron (MN) subtypes and thus their connectivity. During MN differentiation, the Hox clusters undergo a chromatin and 3-D reorganization from a single repressed state to two domains harboring either transcribed or repressed genes. The two chromatin states are insulated by CTCF binding at the boundary, maintaining stable Hox chromatin states inherited though development to ensure proper MN connectivity. Of relevance, we recently demonstrated that the CTCF boundary is essential to normal body patterning during embryonic development in vivo. To understand how CTCF maintains insulated chromatin and 3-D boundaries at Hox clusters we propose: 1) To understand how disrupting the CTCF-mediated chromatin boundary affects subtype identity of spinal MNs; 2) To determine the molecular basis of establishing a CTCF-dependent boundary; 3) An advanced proteomics study to identify factors required by chromatin associated CTCF for its insulator activity, emphasizing those whose interaction is RNA-dependent.

了解控制 Hox 基因表达的 CTCF 边界 概括 基因表达的空间和时间控制对于多细胞的发育至关重要 有机体。尽管增强子和转录之间的循环相互作用发生变化 位点是一种公认​​的基因调控模式，更大的 3D 基因组的贡献 基因表达和正常发育的重组在很大程度上是模糊的。我们建议 实验阐明 CTCF 转录因子如何控制 Hox 处的染色质结构 簇以确保适当的 Hox 基因表达，从而确保身体模式。 在胚胎发育过程中，Hox 基因的精确表达指导细胞识别 它们在身体轴上的相对位置。 Hox 基因被组织成四个簇，每个簇都有各自的 这些簇中的基因以在空间和时间上共线的模式表达 他们的物理染色体组织。沿脊髓的共线 Hox 基因表达 控制运动神经元 (MN) 亚型及其连接性。在 MN 分化过程中， Hox 簇经历染色质和 3-D 重组，从单一抑制状态变为两种状态 包含转录或抑制基因的域。这两种染色质状态是 通过边界处的 CTCF 结合进行隔离，保持稳定的 Hox 染色质状态遗传 通过开发来确保正确的 MN 连接。相关的是，我们最近证明了 CTCF 边界对于胚胎发育过程中正常的身体模式至关重要 体内。了解 CTCF 如何在 Hox 处维持绝缘染色质和 3-D 边界 我们建议：1) 了解如何破坏 CTCF 介导的染色质边界 影响脊髓 MN 的亚型识别； 2) 确定建立的分子基础 CTCF 相关边界； 3) 先进的蛋白质组学研究，以确定所需的因素 染色质相关 CTCF 的绝缘体活性，强调那些相互作用为 RNA依赖性。