Identification of transcriptional determinants of dendritic patterning

树突图案化转录决定因素的鉴定

• 批准号: 7821407
• 负责人: DAVID M MILLER
• 金额: $ 19.12万
• 依托单位: VANDERBILT UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-05-01 至 2012-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7821407
• 关键词: Ablation; Afferent Neurons; Animal Model; Animals; Behavior; Biological Assay; Cadherins; Caenorhabditis elegans; Cells; Cellular biology; Complex; Data Set; Dendrites; Development; Disease; Drosophila genus; Esthesia; Figs - dietary; Foundations; Future; Gene Expression Profiling; Gene Targeting; Genes; Genetic; Genetic Programming; Genetic Screening; Goals; Homeodomain Proteins; Human; Injury; Internet; Lead; Life; Link; Mechanics; Mediating; Messenger RNA; Methods; Modeling; Morphogenesis; Morphology; Nematoda; Nerve; Neurons; Nociception; Nociceptors; Pain; Pattern; Phylogeny; Problem Solving; Process; RNA Interference; Reflex action; Regulation; Role; Sensory; Sensory Process; Skin; Stimulus; Structure; Temperature; Tertiary Protein Structure; Testing; Tissues; Touch sensation; Transcript; Transcription factor genes; Transcriptional Regulation; Withdrawal; Work; axon guidance; homeodomain; mRNA tagging; mutant; neuron development; promoter; public health relevance; receptor; research study; response; transcription factor; web site

DESCRIPTION (provided by applicant): The sensation of pain triggers self-protective responses to noxious insults. Pain is perceived by specialized sensory neurons called nociceptors that utilize elaborate webs of dendritic processes to detect harmful stimuli. These features of nociceptive neurons are universally observed in animals and are thus likely to depend on conserved genetic programs that control nociceptor morphogenesis throughout phylogeny. The mechanisms that govern the creation of these complex structures are poorly understood but recent studies in Drosophila have established that sensory neuron morphology is defined by surprisingly diverse arrays of transcription factors. The identities of downstream genes and their orchestration by these transcriptional networks are largely unknown, however. Here, we propose to solve this problem by exploiting a powerful gene expression profiling method to identify targets of transcription factors that control morphogenesis of a model sensory neuron. In the nematode, C. elegans, a single pair of bilaterally symmetric neurons, PVDL and PVDR envelop the body with a regular array of highly branched dendrites that can be readily visualized with a fluorescent (GFP) marker in living animals. The PVDs respond to strong mechanical force ("harsh touch") to trigger a withdrawal reflex, a behavior indicative of nociceptive function. We have used a cell specific microarray profiling strategy to identify transcripts that are highly expressed in PVD neurons. Specifically, we will: (1) Use available mutants and RNAi clones to test transcription factor genes in this data set for roles in PVD dendritic morphogenesis; (2) Use the mRNA tagging method to reveal genes downstream of the conserved LIM- homeodomain protein, MEC-3, an established determinant of PVD dendritic branching and; (3) Extend this mRNA tagging strategy to at least five additional key transcription factor genes identified in Aim 1. These data sets of transcription factor target genes will provide a foundation for future studies that link transcriptional control to the cell biology of dendritic arborization. We believe that our approach represents a useful alternative to direct studies of mammalian tissues and moreover, that it offers a uniquely powerful strategy for identifying molecules with fundamental, conserved roles in nociceptor morphogenesis. PUBLIC HEALTH RELEVANCE: Specialized nerve cells that mediate the sensation of pain utilize an elaborate array of spaghetti-like sensory processes directly beneath the skin to detect noxious stimuli. To facilitate the identification of genes that govern the creation of these sensory networks, we propose a genetic approach in the nematode C. elegans, a simple model organism with a single pair of PVD sensory neurons that display a stereotypical and readily visible array of nerve processes. The results of this work should reveal similar human genes with crucial roles in the creation of sensory neuron arrays and therefore potentially lead to treatments for injuries or diseases that disrupt human sensory neuron development.

描述（由申请人提供）：疼痛的感觉会触发对有害侮辱的自我保护反应。疼痛是由称为伤害感受器的专门感觉神经元感知的，这些神经元利用精细的树突过程来检测有害刺激。伤害性神经元的这些特征在动物中普遍观察到，因此很可能依赖于控制伤害感受器形态发生的保守遗传程序。控制这些复杂结构的创建的机制知之甚少，但是果蝇的最新研究表明，感觉神经元的形态是由多样化的转录因子阵列出奇地定义的。但是，这些转录网络的下游基因的身份及其编排在很大程度上是未知的。在这里，我们建议通过利用强大的基因表达分析方法来识别控制模型感觉神经元形态发生的转录因子的靶标。在线虫中，秀丽隐杆线虫，一对双侧对称神经元，PVDL和PVDR用常规的高度分支树突笼罩着人体，可以在活动物中使用荧光（GFP）标记来容易地可视化。 PVD响应强大的机械力（“严格触摸”）以触发戒断反射，这是表明伤害功能的行为。我们已经使用了特定于细胞的微阵列分析策略来识别在PVD神经元中高度表达的转录本。具体而言，我们将：（1）使用可用的突变体和RNAi克隆来测试该数据集中的转录因子基因，以在PVD树突形态发生中作用； （2）使用mRNA标记方法揭示了保守的LIM-同源域蛋白下游MEC-3的基因，MEC-3，是PVD树突分支的确定概念，并且； （3）将此mRNA标记策略扩展到AIM 1中鉴定出的至少五个其他关键转录因子基因。这些转录因子目标基因的数据集将为将来的研究提供基础，将转录控制与树突状弧化细胞生物学联系起来。我们认为，我们的方法代表了直接研究哺乳动物组织的有用替代方法，此外，它提供了一种独特的强大策略，用于鉴定在伤害感受器形态发生中具有基本，保守的作用的分子。公共卫生相关性：介导疼痛感觉的专门神经细胞利用直接在皮肤下方的意大利面条样感觉过程来检测有害刺激。为了促进控制这些感觉网络创建的基因的鉴定，我们在线虫C.秀丽隐杆线虫中提出了一种遗传方法，这是一种简单的模型生物体，具有一对PVD感觉神经元，显示出刻板的观念且易于可见的神经过程。这项工作的结果应揭示出类似的人类基因，在创建感觉神经元阵列中具有至关重要的作用，因此有可能导致破坏人类感觉神经元发展的损伤或疾病的治疗。