Development of Cranial Motor Neurons

颅运动神经元的发育

• 批准号: 6639684
• 负责人: Anand Chandrasekhar
• 金额: $ 21.56万
• 依托单位: UNIVERSITY OF MISSOURI-COLUMBIA
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-06-01 至 2005-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6639684
• 关键词: animal genetic material tag; biological signal transduction; cell migration; cell transplantation; confocal scanning microscopy; developmental neurobiology; embryo /fetus cell /tissue; fluorescence microscopy; gene induction /repression; gene mutation; genetically modified animals; head; in situ hybridization; motor neurons; neural plate /tube; neurogenesis; protein structure function; skull; transcription factor; zebrafish

DESCRIPTION (provided by applicant): Neuronal induction and migration are fundamental processes in nervous system development, and many human neurological disorders are caused by severe deficiencies in these processes. Our focus is the cranial motor neurons (CMNs), which control vital functions such as chewing, swallowing, and speech in humans. Our long-term goal is to elucidate the cellular and molecular mechanisms underlying the induction and migration of CMNs in the powerful model vertebrate, the zebrafish embryo. Secreted proteins of the sonic hedgehog (Shh) family are essential for vertebrate motor neuron induction. However, little is known about the mechanisms by which Shh signaling pathway components, including the Gli1 and Gli2 transcription factors, specify different types of motor neurons (CMNs and spinal motor neurons (SMNs)) along the anterior-posterior axis of the neural tube. The cellular mechanisms underlying tangential migration of CMNs following induction are equally obscure. Our preliminary studies demonstrate that the zebrafish detour (dtr/gli 1) and you-too (yot/gli2) genes have specific functions in CMN and SMN induction, and that mutations in the trilobite (tri) and valentino (val) genes disrupt particular events during tangential CMN migration. The studies we propose here will define the mechanisms of CMN specification and tangential migration. (1) We will determine whether Gli1 and Gli2 are necessary and sufficient for CMN and SMN induction (a) by characterizing motor neuron development in yot mutants, (b) by determining whether gli1 and gli2 are co-expressed in motor neurons, and (c) by analyzing CMN and SMN induction in dtr; yot double mutants, and following gli1 and gli2 overexpression in wildtype and dtr mutant embryos. (2) We will evaluate the function of Shh pathway components encoded by the chameleon (con) and iguana (igu) genes in CMN and SMN induction. (3) We will determine whether the CMN migration defects of tri and val mutants are caused by specific defects in dynamic cellular behaviors (a) by genetic mosaic analysis of tri mutants, and (b) by analyzing dynamic cellular behaviors of migrating CMNs in wildtype, and tri and val mutant embryos by time-lapse microscopy. The availability of key zebrafish mutants, the ability to employ gain- and loss-of-function approaches, the optical clarity of the zebrafish embryo, and the ability to perform genetic mosaic analysis and time-lapse microscopy represent a powerful combination of tools that will enable us to define the functions of particular genes in CMN development at the cellular and molecular levels. Our studies on motor neuron induction and migration will provide fundamental insights into the mechanisms underlying these processes essential for normal brain development and function.

描述(申请人提供)：神经元的诱导和迁移 神经系统发育的基本过程，以及许多人类 神经性疾病是由这些过程中的严重缺陷引起的。 我们的重点是控制重要功能的颅运动神经元(CMN) 例如在人类中的咀嚼、吞咽和说话。我们的长期目标是 阐明诱导和诱导的细胞和分子机制 CMN在强大的模式脊椎动物斑马鱼胚胎中的迁移。 Sonic Hedgehog(Shh)家族的分泌蛋白是 脊椎动物运动神经元的诱导。然而，人们对此知之甚少 Shh信号通路组件，包括Gli1和 Gli2转录因子，指定不同类型的运动神经元(CMN和 脊髓运动神经元(SMN)沿神经前后轴分布 管子。CMN切向迁移的细胞机制 归纳法同样晦涩难懂。我们的初步研究显示， 斑马鱼迂回(dtr/gli 1)和You-Too(yot/gli2)基因具有特异性 在CMN和SMN诱导中的作用，以及三叶虫(Tri)的突变 和华伦天奴(Val)基因干扰切线CMN中的特定事件 迁移。我们在这里提出的研究将定义CMN的机制 规范和切向偏移。(1)我们将确定Gli1和 Gli2是CMN和SMN诱导(A)的必要条件和充分条件 表征yot突变体中运动神经元的发育，(B)通过确定 Gli1和Gli2在运动神经元中是否共表达，以及(C)通过分析 CMN和SMN在dtr；yot双突变体中的诱导，以及在Gli1和gli2之后 野生型和dtr突变胚胎中的过表达。(2)我们会评估 变色龙(CON)和鬣蜥编码的Shh途径成分的功能 (IGU)基因在CMN和SMN诱导中的作用。(3)我们将确定CMN是否 Tri和val突变体的迁移缺陷是由 通过三个突变体的遗传镶嵌分析，动态细胞行为(A)，以及 (B)通过分析野生型CMN迁移的动态细胞行为，以及 用时间推移显微镜观察tri和val突变胚胎。密钥的可用性 斑马鱼突变体，使用功能增减方法的能力， 斑马鱼胚胎的光学清晰度，以及进行遗传 镶嵌分析和延时显微镜代表了 这些工具将使我们能够定义CMN中特定基因的功能 在细胞和分子水平上的发育。我们对运动神经元的研究 诱导和迁移将提供对这些机制的基本见解 这些过程对正常的大脑发育和功能至关重要。