Genetic Underpinnings of ipRGC Diversity

ipRGC 多样性的遗传基础

• 批准号: 10744473
• 负责人: Tiffany M. Schmidt
• 金额: $ 52.86万
• 依托单位: NORTHWESTERN UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-09-30 至 2027-02-28
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10744473
• 关键词: Address; Adult; Behavior; Brain; Cell physiology; Cells; Cellular Morphology; Cellular Structures; Characteristics; Complement; Data; Development; Embryonic Development; Eye; Gene Expression; Gene Expression Profile; Gene Expression Profiling; Genes; Genetic; Genetic Models; Genetic Transcription; Genomics; Goals; Individual; Label; Light; Location; Measurement; Methods; Molecular; Morphology; Mus; Nervous System; Neurons; Organism; Pattern; Photoreceptors; Physiological; Physiology; Population; Property; Research; Resolution; Retina; Retinal Ganglion Cells; Role; Shapes; Specific qualifier value; Structure; System; Testing; Transcription Factor Brn-3B; Transcriptional Regulation; cell type; experimental study; ganglion cell; genetic approach; insight; melanopsin; novel; overexpression; patch clamp; postmitotic; programs; single nucleus RNA-sequencing; single-cell RNA sequencing; tool; transcription factor; transcriptome; transcriptomics

PROJECT SUMMARY Light is a profoundly important regulator of physiology and behavior across a wide range of organisms. Light information is relayed via diverse retinal ganglion cell types to approximately 50 distinct targets in the brain. The melanopsin-expressing, intrinsically photosensitive retinal ganglion cells (ipRGCs) represent 6 of the ~40-50 retinal ganglion cell types present in the mouse retina. M1-M6 ipRGCs are defined by a distinct complement of subtype-defining morphological, physiological, and transcriptional characteristics. However, how this cellular diversity is achieved is largely unknown. This proposal will investigate the molecular underpinnings of ipRGC diversity. ipRGCs also represent an excellent microcosm for studying diversity in the larger RGC population because 1) ipRGCs can be specifically manipulated with multiple, existing genetic tools, 2) transcriptional profiling has revealed gene expression programs that designate ipRGC subtypes, and 3) the diversity of ipRGC subtype morphology, physiology, central projections, and roles in behavior are a broad, and representative subsample of subtype-defining features of RGCs. Thus, ipRGCs are an approachable, representative, and genetically malleable population in which to study cellular diversity. In the experiments outlined below, we will exploit the advantages of the ipRGC system by combining targeted, single cell measurements of ipRGC morphology and physiology with powerful, large-scale transcriptomic approaches in new genetic models to assess how the full range of ipRGC subtypes are established. Brn3b (Pouf42) is a transcription factor involved in RGC specification, and its expression is maintained in ipRGC subtypes into adult stages, where it is poised to influence developmental and adult gene expression programs that give rise to the subtype-defining properties of ipRGCs. This proposal will test the hypothesis that Brn3b actively shapes the morphological, physiological, and transcriptional identity of ipRGC subtypes. In Aim 1 we will use new mouse lines to manipulate Brn3b expression in ipRGCs during development and adulthood to determine the consequences of increasing or reducing Brn3b levels on the morphophysiological features of ipRGCs. In Aim 2 we will determine the roles of Brn3b in shaping gene expression patterns across retinal development and within individual ipRGC subtypes. Excitingly, our preliminary data indicate that Brn3b expression levels in ipRGC subtypes not only correlate with multiple ipRGC features, but also actively regulate defining features of ipRGC subtypes, suggesting that Brn3b is repurposed throughout development and adulthood to fine-tune ipRGC circuit structure and function. These studies will generate a blueprint for understanding how the patterning of transcriptional programs establishes diverse cellular identities in the retina and nervous system.

项目概要 光是多种生物体生理和行为的极其重要的调节剂。光 信息通过不同类型的视网膜神经节细胞传递到大脑中大约 50 个不同的目标。这 表达黑视蛋白、本质上感光的视网膜神经节细胞 (ipRGC) 代表约 40-50 个视网膜神经节细胞中的 6 个 小鼠视网膜中存在的视网膜神经节细胞类型。 M1-M6 ipRGC 由不同的补充定义 亚型定义的形态学、生理学和转录特征。然而，这种蜂窝 多样性的实现在很大程度上是未知的。该提案将研究分子基础 ipRGC 多样性。 ipRGC 还代表了研究更大 RGC 多样性的绝佳缩影 群体，因为 1) ipRGC 可以使用多种现有的遗传工具进行专门操作，2) 转录分析揭示了指定 ipRGC 亚型的基因表达程序，以及 3) ipRGC 亚型形态、生理学、中心预测和行为作用的多样性是广泛的，并且 RGC 亚型定义特征的代表性子样本。因此，ipRGC 是一种平易近人、 具有代表性和遗传可塑性的群体，用于研究细胞多样性。在 实验概述如下，我们将通过结合有针对性的、单一的来利用 ipRGC 系统的优势 使用强大的大规模转录组学方法对 ipRGC 形态和生理学进行细胞测量 在新的遗传模型中评估如何建立全系列 ipRGC 亚型。 Brn3b (Pouf42) 是 参与 RGC 规范的转录因子，其表达在 ipRGC 亚型中维持到成年 阶段，它将影响发育和成人基因表达程序，从而产生 ipRGC 的亚型定义属性。该提案将测试 Brn3b 主动塑造的假设 ipRGC 亚型的形态、生理和转录特性。在目标 1 中，我们将使用新的 小鼠品系在发育和成年期间操纵 ipRGC 中 Brn3b 的表达，以确定 增加或减少 Brn3b 水平对 ipRGC 形态生理特征的影响。目标 2 我们将确定 Brn3b 在塑造视网膜发育和内部基因表达模式中的作用 单独的 ipRGC 亚型。令人兴奋的是，我们的初步数据表明 ipRGC 中 Brn3b 的表达水平 亚型不仅与多种 ipRGC 特征相关，而且还主动调节 ipRGC 的定义特征 亚型，表明 Brn3b 在整个发育和成年期被重新利用，以微调 ipRGC 电路 结构和功能。这些研究将生成一个蓝图，用于理解如何形成模式 转录程序在视网膜和神经系统中建立了不同的细胞身份。