The role of BARHL2 in the mosaic pattering and dendritic tiling of retinal amacri

BARHL2 在视网膜 amacri 的马赛克图案和树突状平铺中的作用

• 批准号: 8585275
• 负责人: Lin Gan
• 金额: $ 23.03万
• 依托单位: UNIVERSITY OF ROCHESTER
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-09-01 至 2015-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8585275
• 关键词: Address; Amacrine Cells; Axon; Blindness; Cell Adhesion Molecules; Cell Differentiation process; Cells; ChIP-seq; Characteristics; Coupled; DNA Sequence; Defect; Dendrites; Development; Down Syndrome Cell Adhesion Molecule; Drosophila genus; Dyes; Ensure; Event; Exhibits; Failure; Foundations; Future; Ganglion Cell Layer; Gene Expression Profile; Gene Targeting; Genes; Genetic; Individual; Injection of therapeutic agent; Inner Nuclear Layer; Label; Link; Molecular; Morphology; Mus; Mutant Strains Mice; Nervous System Physiology; Nervous system structure; Neurites; Neurons; Pathway interactions; Pattern; Phenotype; Play; Process; Property; Protein Kinase; Recovery; Regulatory Pathway; Research; Retina; Retinal; Role; Sensory; Shotgun Sequencing; Staging; Structure; Technology; Time; Vision; cell type; cholinergic; chromatin immunoprecipitation; density; ganglion cell; gene discovery; homeodomain; neural circuit; neuronal cell body; novel; public health relevance; response; retinal neuron; transcription factor; transcriptome sequencing; visual information

PROJECT SUMMARY Our accurate vision depends on the flow of visual information through precisely wired connections between axons and dendrites of different retinal neurons. In the retina, neurons occupy spatial domains and arborize their dendrites, which require the proper distribution of their cell bodies and dendritic arbors. Cell bodies of the same type of neurons are spaced out in a process called mosaic patterning, and their dendrites establish a zone within which other cells of the same type are excluded, a process called tiling. In addition, the neurites from an individual cell display self-avoidance properties. In contrast to the excellent progress made in discovering genes and mechanisms of retinal cell fate determination and differentiation, relatively little is known about the molecular mechanisms underlying the mosaic patterning and tiling processes in the retina as well as in other nervous systems. Not until recently, studies show that in mice mutant for Down syndrome cell adhesion molecule (DSCAM), DSCAM-LIKE1 (DSCAML1), MEG10, and PCDH, certain types of retinal amacrine and ganglion cells exhibit defects in the spacing of cell bodies and in the dendritic arborization, which begins to implicate the roles of unique classes of cell adhesion molecules (CAMs) in regulating these processes in the vertebrate retina. Nevertheless, we have yet to uncover the other molecules involved in these processes in each of the nearly 80 retinal cell types and subtypes, and more importantly, to identify and characterize the entire genes and genetic pathways that govern the formation of functional neural circuitry. In the past, this question has been hard to address due to the lack of a suitable molecule. Here, we show that in mice lacking BARHL2, a BAR-homeodomain transcription factor, starburst amacrine cells in the ganglion cell layer have aggregated dendrites and clumped cell bodies, indicating Barhl2's role in self-avoidance. Being the first transcription factor implicated in neuronal mosaic patterning and tiling processes, BARHL2 offers a unique opportunity to ultimately identify genetic pathways of neuronal mosaic patterning and tiling formation. In this proposal, we will fully characterize the mosaic patterning and tiling phenotypes of starburst amacrine cells in the ganglion cell layer of the Barhl2-null retina. Second, to recover the genetic pathway of self-avoidance, we will perform RNA-Seq of Barhl2 wild type and null starburst amacrine cells and BARHL2 ChIP-Seq to screen for downstream target genes of Barhl2 and to identify the transcriptional network regulating the tiling and mosaic patterning processes of starburst amacrine cells. Together, these studies will define the role of Barhl2 in regulating the tiling and mosaic patterning processes of starburst amacrine cells and elucidate the transcriptional events that occur downstream of Barhl2.

项目概要 我们准确的视觉取决于通过精确的有线连接的视觉信息流 不同视网膜神经元的轴突和树突之间。在视网膜中，神经元占据空间域并 它们的树突呈树枝状，这需要它们的细胞体和树突乔木的适当分布。细胞 相同类型神经元的体在称为马赛克图案的过程中间隔开，并且它们的树突 建立一个区域，在该区域内排除相同类型的其他单元格，这个过程称为平铺。此外， 单个细胞的神经突表现出自我回避特性。与取得的巨大进步相比 发现视网膜细胞命运决定和分化的基因和机制，人们知之甚少 关于视网膜马赛克图案和平铺过程的分子机制以及 在其他神经系统中。直到最近，研究表明小鼠唐氏综合症细胞突变 粘附分子 (DSCAM)、DSCAM-LIKE1 (DSCAML1)、MEG10 和 PCDH、某些类型的视网膜 无长突细胞和神经节细胞在细胞体间距和树突状树枝化方面表现出缺陷，这 开始暗示独特类别的细胞粘附分子（CAM）在调节这些细胞中的作用 脊椎动物视网膜中的过程。然而，我们尚未发现参与这些过程的其他分子。 近 80 种视网膜细胞类型和亚型中的每一种的过程，更重要的是，识别和 描述控制功能神经回路形成的整个基因和遗传途径。在 过去，由于缺乏合适的分子，这个问题一直很难解决。在这里，我们表明，在 缺乏 BARHL2（一种 BAR 同源域转录因子）的小鼠，神经节细胞中出现星爆型无长突细胞 层具有聚集的树突和聚集的细胞体，表明 Barhl2 在自我回避中的作用。成为 BARHL2 是第一个参与神经元镶嵌图案和平铺过程的转录因子，它提供了独特的 最终确定神经元镶嵌图案和平铺形成的遗传途径的机会。在这个 建议，我们将充分表征星爆无长突细胞的马赛克图案和平铺表型 Barhl2 缺失视网膜的神经节细胞层。其次，为了恢复自我回避的遗传途径，我们 将进行 Barhl2 野生型和 null starburst 无长突细胞的 RNA-Seq 和 BARHL2 ChIP-Seq 进行筛选 寻找 Barhl2 的下游靶基因并鉴定调节平铺和 星爆无长突细胞的镶嵌图案过程。这些研究将共同​​确定 Barhl2 的作用 调节星爆无长突细胞的平铺和镶嵌图案过程并阐明 Barhl2 下游发生的转录事件。