DEVELOPMENT OF MOTONEURONAL CONNECTIVITY

运动神经连接的发展

• 批准号: 2264067
• 负责人: Monte Westerfield
• 金额: $ 24.76万
• 依托单位: UNIVERSITY OF OREGON
• 依托单位国家: 美国
• 财政年份: 1984
• 资助国家: 美国
• 起止时间: 1984-07-01 至 1998-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2264067
• 关键词: biological signal transduction; cell cell interaction; developmental genetics; developmental neurobiology; embryo /fetus; embryo /fetus tissue /cell culture; fluorescent dye /probe; gene induction /repression; gene mutation; genetic promoter element; genetic regulation; genetically modified animals; lasers; motor neurons; mutant; myoblasts; myogenesis; neuromuscular junction; spinal cord; spine; vertebrate embryology; zebrafish

Inductive interactions between cells regulate many aspects of vertebrate development, including formation and patterning of the nervous system. Failures of inductive signaling give rise to a wide variety of birth and developmental defects. Despite the obvious importance and many types of inductive interactions required for vertebrate development, the cellular and molecular mechanisms that regulate such interactions are, for the most part, poorly understood. This proposal seeks a more detailed understanding of a developmental signaling process that induces formation of the first muscle cells, termed muscle pioneers. Analysis of zebrafish embryos has shown that muscle pioneers arise and take on their specialized cell-fates, distinct from other muscle cells, as a result of inductive influences from the notochord. To learn when and where these interactions between the notochord and muscle occur, notochord precursors cells, will be a) removed by laser ablation at various times during the inductive process, b) followed with fluorescent dyes in live developing embryos, and c) grown in culture in the presence of muscle precursors. To understand the genetic regulation of the induction process, interactions between two mutations, ntl and spt, that perturb formation of muscle pioneers, will be characterized. The induction of muscle pioneers will be assayed after transplanting a) wild-type notochord precursor cells into ntl mutants, which lack notochords, b) notochord precursors from spt mutants, which lack muscle pioneers, into ntl mutants, and c) wild-type precursors into ntl/spt double mutants. By determining the conditions for rescue of notochord, muscle pioneers, and both, the precise cellular requirements for the induction and the functions of the genes identified by these mutations will be learned. To begin identifying the molecular genetic mechanisms underlying the inductive process, genes expressed in muscle pioneers in response to notochord induction will be characterized by analyzing their promoters and their functions in transgenic fish, and new mutations that affect the formation of muscle pioneers and muscle patterning will be recovered and characterized.

细胞间的诱导相互作用调节脊椎动物的许多方面 发育，包括神经系统的形成和模式。 诱导信号的失败引起了各种各样的出生和 发育缺陷尽管有明显的重要性和许多类型的 脊椎动物发育所需的诱导性相互作用， 调节这种相互作用的分子机制， 部分，不太了解。 该提案旨在更详细地了解一个发展中的 诱导第一个肌细胞形成的信号传导过程，称为 肌肉先锋对斑马鱼胚胎的分析表明， 先驱者出现并承担其特殊的细胞命运， 其他肌肉细胞，作为诱导影响的结果， 脊索 为了了解这些脊索和 肌肉发生，脊索前体细胞，将a）通过激光去除 在诱导过程中的不同时间进行烧蚀，B）随后是 活的发育中的胚胎中的荧光染料，和c）在培养物中生长， 肌肉前体的存在。 为了了解诱导过程的遗传调控， 两种突变ntl和spt之间的相互作用， 肌肉先锋，将被描述。肌肉先锋的诱导 a）野生型脊索前体细胞 转化为缺乏脊索的ntl突变体，B）来自spt的脊索前体 缺乏肌肉先驱的突变体转化为ntl突变体，和c）野生型 前体转化成ntl/spt双突变体。通过确定条件， 拯救脊索，肌肉先驱，以及两者，精确的细胞 诱导的要求和鉴定的基因的功能 通过这些突变将被学习。 为了开始确定潜在的分子遗传机制， 诱导过程中，基因表达的肌肉先锋，以回应 脊索诱导将通过分析它们的启动子来表征， 它们在转基因鱼中的功能，以及影响转基因鱼的新突变。 肌肉先锋和肌肉图案的形成将被恢复， 表征了