Regulation of Synapse Morphogenesis in Drosophila

果蝇突触形态发生的调控

• 批准号: 9262285
• 负责人: David L. Van Vactor
• 金额: $ 37.08万
• 依托单位: HARVARD MEDICAL SCHOOL
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-04-01 至 2019-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9262285
• 关键词: Address; Antibodies; Architecture; Bioinformatics; Biological; Biological Assay; Biological Models; Biology; Brain region; Cell Communication; Cells; Chemical Synapse; Collection; Complex; Data; Defect; Dependence; Detection; Development; Dissection; Drosophila genus; Electrophysiology (science); Embryo; Employee Strikes; Family; Funding; Gene Mutation; Gene Targeting; Genes; Genetic; Genetic Models; Genetic Transcription; Genetic Translation; Glutamates; Goals; Grant; Growth; In Vitro; Individual; Informatics; Knowledge; Letters; Logic; Maintenance; Maps; Mediating; Mental disorders; Messenger RNA; Methods; MicroRNAs; Microscopy; Modeling; Molecular; Morphogenesis; Motor Neurons; Muscle; Muscle Cells; Nervous System Physiology; Nervous system structure; Neuromuscular Junction; Neurons; Orthologous Gene; Pathway interactions; Phenotype; Phylogeny; Porifera; Positioning Attribute; Process; Proteins; RNA; Reagent; Regulation; Resolution; Resources; Shapes; Side; Signal Pathway; Signal Transduction; Source; Specificity; Structure; Synapses; Synaptic Transmission; Synaptosomes; System; Technology; Testing; Transgenic Organisms; Translations; Transmission Electron Microscopy; Untranslated RNA; Work; cell type; experimental study; gene function; human disease; improved; in vivo; mRNA Expression; mRNA Stability; morphometry; multilevel analysis; mutant; nervous system disorder; neural circuit; novel; overexpression; postsynaptic; presynaptic; public health relevance; relating to nervous system; sensor; spatiotemporal; synaptic function; synaptogenesis; tool; trafficking; transcriptome

 DESCRIPTION (provided by applicant): The formation and maturation of chemical synapses is essential to all major functions of the nervous system. Synaptogenesis represents a complex process of coordinated morphogenesis governed by highly conserved signaling pathways and intracellular effector proteins. Over the past decade, accumulated evidence revealed that this process is under regulatory control of various post-transcriptional mechanisms, from RNA trafficking to local translation, that offer the spatial acuity needed for the complex architectureof neurons and neural circuits. Amongst the sequence-specific regulators that may shape the translation and stability of key neuronal mRNAs, microRNAs (miRs) have recently emerged as a rich potential source. This large and diverse class of non-coding RNA is expressed abundantly in the nervous system, with hundreds of miRs localized to different brain regions, specific neuronal subpopulations and synaptic compartments. Despite impressive advances in the sequencing and informatics technologies required to detect miRs and their targets within the transcriptome, a comprehensive analysis of miR functions required for synaptogenesis was largely limited to in vitro systems where the endogenous cell-cell interaction and developmental signals are lost. In order to address this challenge, we spent the first cycle of funding on this grant developing genetic tools for conditional manipulation and detection of miR function in a model system that has proven to be a powerful model of excitatory glutamatergic synaptic transmission: the Drosophila neuromuscular junction (NMJ). We used our toolkit to dissect a novel trans-synaptic mechanism by which miR-8 regulates coordinated morphogenesis of pre- and post-synaptic compartments during development, in addition to experiments to prove the efficacy of these tools for a variety of experimental questions. We then created a collection of improved reagents to analyze synapse- regulatory function for 141 miRs, and completed a screen revealing that there are dozens of well-conserved miRs required for distinct aspects of NMJ formation. This pioneering effort has put us in a unique position to map out the spatio-temporal landscape of miR regulation for each of the stages of synapse formation and maturation in this system. We have identified two particular miRs that exert potent and reciprocal regulatory effects on opposite sides of the synapse: miR-34 is required in muscle to control addition and spacing of presynaptic boutons, whereas, miR-137 is required in neurons to restrict the overall growth of presynaptic arbors. Both miR-34 and miR-137 show striking conservation to genes implicated in neurological and psychiatric disease, confirming that they are functionally relevant across phylogeny, and suggesting that deeper analysis in our model can be used to ask if the downstream mechanisms are also conserved. In parallel with experiments to define the miRs that act in motor neurons and muscles to shape NMJ development, we will pursue a multi-level analysis of phenotypes and miR target gene networks in order to understand the cellular and molecular logic of the mechanisms by which conserved miRs control synaptogenesis.

 描述（通过应用程序提供）：化学突触的形成和成熟对于神经系统的所有主要功能至关重要。突触发生代表了由高度组成的信号通路和细胞内效应蛋白控制的协调形态发生的复杂过程。在过去的十年中，积累的证据表明，从RNA贩运到局部翻译的各种转录后机制的调节控制，这些过程提供了神经元和神经元电路复杂结构所需的空间敏锐度。在可能塑造关键神经元mRNA的翻译和稳定性的序列特异性调节剂中，microRNA（miR）最近成为了丰富的潜在来源。这种大而多样化的非编码RNA在神经系统中彻底表达，数百个MIR位于不同的大脑区域，特定的神经元亚群和突触室。尽管在转录组中检测MIR及其目标所需的测序和信息性技术的令人印象深刻的进步，但对突触发生所需的MIR功能的全面分析在很大程度上仅限于体外系统，在体外系统中，内源性细胞细胞相互作用和发育信号丢失。为了应对这一挑战，我们将资金的第一个循环花在了这项赠款上开发的遗传工具，以在模型系统中有条件地操纵和检测MIR功能，该模型系统被证明是兴奋性谷氨酸能突触传播的强大模型：果蝇神经肌肉肌肉连接（NMJ）。我们使用工具包剖析了一种新型的反呼吸机制，通过该机制，miR-8通过在开发过程中调节前和突触后隔室的配位形态发生，此外还可以证明这些工具在各种实验性问题上证明这些工具的有效性。然后，我们创建了一系列改进的试剂，以分析141个MIR的突触调节功能，并完成了一个屏幕，揭示了NMJ形成不同方面所需的数十个保存的miR。这项开创性的工作使我们处于独特的位置，以绘制MIR调节的空间范围景观，用于该系统中突触形成和成熟的每个阶段。我们已经确定了两个对突触相对侧的潜在和相互调节作用的特定miR：肌肉中需要miR-34来控制突触前胎胎的添加和间隔，而神经元中需要miR-137来限制突触前轴向的整体生长。 miR-34和miR-137均表现出对神经和精神病疾病中隐含的基因的惊人保守性，证实它们在系统发育中具有功能相关，并提出在我们的模型中可以使用更深入的分析来询问下游机制是否也保存。与定义在运动神经元和肌肉中起作用的MIR以塑造NMJ发育的实验，我们将对表型和MIR靶基因网络进行多层次分析，以了解保守MIR控制突触发生的机制的细胞和分子逻辑。