Translational control of a complete developing sensory circuit

项目摘要 神经系统的发育需要产生不同的神经元类型， 彻底改变它们的形状和生理机能，形成巨大的互联网络。每个过程都需要 精确的基因调控技术创新大大增加了我们可以 基于转录组学或表观遗传学区分神经元身份或阶段。然而，指导原则 基因表达的转录后控制，这是神经发育和稳态所必需的， 包括RNA结合蛋白（RBP）和miRNA在内的调节因子尚未在类似的水平上被定义。 系统层面。由于许多神经退行性疾病与受损的RBP-RNA有关， 相互作用，并且存在对用于治疗的改进的细胞类型工程策略的巨大需求， 在这个过程中是至关重要的。我建议使用果蝇视觉系统作为模型来研究后- 在整个神经感觉系统的规范和布线过程中的转录调控。具体来说， 一项提案集中在mRNA翻译抑制的调节上，这是两者的保守特征。 脊椎动物和无脊椎动物的神经元命运多样化和分化。单细胞转录组图谱 最近描述了发育中的视觉系统或视叶的转录组， 在整个发育过程中，视叶中的神经元类型。与其他模型系统的结果一致， 在未成熟神经元的转录本中检测到许多与终末神经元功能相关的基因 在功能上需要它们之前，并且两个选定的基因不存在相应的蛋白质 研究了我的目标是通过首先进行全组织和 选择视叶发育过程中的细胞特异性核糖体分析，并确定上游控制 这一过程使用生物信息学和遗传学的组合（目标1）。接下来我将梳理分子 以及与不同神经元信号通路相关的两个基因被抑制的细胞机制 在翻译水平上评估它们的表达是如何协调的（目标2）。最后，我将调整一个单细胞 翻译分析技术，scRibo-STAMP，在果蝇视觉系统中分析所有光学翻译 叶神经元在规格和布线。结合基于机器学习的分析，我将预测 RBP/miRNA-RNA靶向相互作用，以获得对RNA调控网络如何形成的基本见解 (Aim 3）。总之，这项研究将提供重要的见解，翻译调控的作用，在 神经系统的形成与人类发育和健康有关。

Project Summary Development of the nervous system requires the generation of diverse neuronal types that subsequently drastically alter their shape and physiology to form vast interconnected networks. Each process requires precise gene regulation. Technological innovations have drastically increased the scale at which we can distinguish neuronal identities or stages based on transcriptomics or epigenetics. However, principles guiding post-transcriptional control of gene expression, which is essential for neural development and homeostasis, by regulatory factors including RNA-binding proteins (RBP) and miRNAs has not been defined at a similar systematic level. As numerous neurodegenerative disorders have been linked to impaired RBP-RNA interactions, and there is a huge need for improved cell type engineering strategies for therapeutics, insight into this process is critically important. I propose to use the Drosophila visual system as a model to study post- transcriptional regulation during specification and wiring of an entire neural sensory system. Specifically, this proposal focuses on the regulation of mRNA translational repression, which is a conserved feature of both neuronal fate diversification and differentiation in vertebrate and invertebrates. A single-cell transcriptomic atlas of the developing visual system, or optic lobe, was recently described which defines the transcriptome of each neuronal type in the optic lobe throughout development. Consistent with results from other model systems, many genes associated with terminal neuronal function were detected at transcripts in the immature neurons well before they are functionally required, and the corresponding protein was absent for two selected genes studied. I aim to define the scope of translational regulation in this system by first performing whole-tissue and select cell-specific ribosome profiling of the optic lobe over development, and determine the upstream control of this process using a combination of bioinformatics and genetics (Aim 1). Next I will tease apart the molecular and cellular mechanism by which two genes associated with different neuron signaling pathways are repressed at the translational level to assess how their expression is coordinated (Aim 2). Finally, I will adapt a single-cell translation profiling technique, scRibo-STAMP, in the Drosophila visual system to profile translation of all optic lobe neurons during specification and wiring. Combined with machine-learning based analysis, I will predict RBP/miRNA-RNA target interactions to gain fundamental insight into how RNA regulatory networks are shaped (Aim 3). Together this study will provide significant insights into the role of translational regulation during formation of the nervous system relevant to both human development and health.