Axonal pathway selection in the zebrafish embryo

斑马鱼胚胎中的轴突通路选择

基本信息

批准号：
7887216
负责人：
Michael Granato
金额：
$ 32.35万
依托单位：
UNIVERSITY OF PENNSYLVANIA
依托单位国家：
美国
项目类别：
财政年份：
1999
资助国家：
美国
起止时间：
1999-07-01 至 2015-02-28
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7887216
关键词：
Agrin Alleles Animals Anterior Antibodies Automobile Driving Axon Binding Biological Cell Polarity Cellular Structures Characteristics Child health care Cholinergic Receptors Complement Congenital Myasthenic Syndromes Data Defect Development Disease Dominant-Negative Mutation Elements Embryo Embryonic Development Event Genes Genetic Genetic Screening Growth Cones Hour Human Inborn Genetic Diseases Life Ligands Location Membrane Modeling Molecular Molecular Cloning Motor Motor Neurons Muscle Muscle Cells Muscle Fibers Muscle-Specific Kinase Mutation Natural regeneration Nature Nerve Pathway interactions Penetrance Phenotype Play Positioning Attribute Process Proteins Publishing Recruitment Activity Regulator Genes Role Signal Pathway Signal Transduction Spinal Cord Staining method Stains Synapses Testing Time Tissues Transgenic Organisms Vertebrates Zebrafish axon growth axon guidance axonal guidance axonal pathfinding cellular imaging gaze palsy horizontal gaze human disease in vivo motor control mutant nerve injury neuromuscular peripheral membrane protein 43K postsynaptic presynaptic public health relevance receptor research study response scoliosis synaptogenesis

项目摘要

DESCRIPTION (provided by applicant): The process of motor axonal guidance and the ensuing process of neuromuscular synapse formation are spatially and temporally precisely coordinated, yet how this achieved at the molecular-cellular level is not well understood. One key player in this process is the vertebrate specific gene muscle specific kinase, MuSK, which aligns the path of incoming motor axon with the location of postsynaptic elements to the muscle center. We have compelling evidence that zebrafish unplugged/MuSK binds wnt11r to initiate this process through a dishevelled dependent signaling cascade, thereby restricting growth cones and synaptic prepattern to the muscle center through a mechanism reminiscent of planar cell polarity (PCP). A major implication is that the spatial alignment between presynaptic growth cones and postsynaptic development might be transmitted through a signaling pathway known to position cellular structures or processes at defined positions within the tissue plane. Specifically, unplugged/ MuSK might play a broader than previously anticipated role to organize a common central muscle zone to which pioneering growth cones and the first acetylcholine receptor clusters are restricted. The objective of the studies described here are threefold. (1) Determine the mechanism through which Wnt signals activate unplugged/MuSK function (through functional studies and live cell imaging to examine the cellular localization of unplugged/MuSK in response to Wnt signals). (2) Determine the extent of similarity between 'classical' PCP and unplugged/MuSK downstream signaling (through functional studies and live cell imaging). (3) Lastly, to maximize our understanding of motor axon guidance, it is critical to analyze and clone two newly identified genetic players in this process, turn out and rush hour (through cellular experiments and molecular cloning). These studies are directly relevant to the study of human disease, since genes known to direct axonal growth and synapse formation are implicated in the cause of human disease states and human inherited disorders, and might also play a role in regeneration after nerve injury. PUBLIC HEALTH RELEVANCE: How motor axons navigate without errors over long distances and select their appropriate synaptic muscle targets, is not fully understood. Using genetic studies, live cell imaging and molecular biological studies, this proposal aims to understand how a key regulator gene, muscle specific kinase (MuSK), controls both axonal pathfinding and synapse formation. This is directly relevant to the study of child health and inherited disorders, because genetic defects in axonal pathfinding and synapse formation cause disorders such as horizontal gaze palsy with progressive scoliosis or congenital myasthenic syndrome.

描述（由申请人提供）：运动轴突引导的过程和随后的神经肌肉突触形成的过程在空间和时间上精确协调，但如何在分子细胞水平上实现这一点尚不清楚。这一过程中的一个关键角色是脊椎动物特异性基因肌肉特异性激酶 MuSK，它将传入运动轴突的路径与突触后元件到肌肉中心的位置对齐。我们有令人信服的证据表明，斑马鱼拔出/MuSK结合wnt11r，通过混乱的依赖信号级联启动这一过程，从而通过一种让人想起平面细胞极性（PCP）的机制将生长锥和突触预模式限制在肌肉中心。主要含义是，突触前生长锥和突触后发育之间的空间对齐可能通过已知将细胞结构或过程定位在组织平面内的限定位置的信号传导途径来传递。具体来说，Unplugged/MuSK 可能会发挥比之前预期更广泛的作用，以组织一个共同的中央肌肉区域，先驱生长锥和第一个乙酰胆碱受体簇被限制在该区域。这里描述的研究有三个目的。 (1)确定Wnt信号激活unplugged/MuSK功能的机制（通过功能研究和活细胞成像来检查unplugged/MuSK响应Wnt信号的细胞定位）。 (2) 确定“经典”PCP 和未插入/MuSK 下游信号传导之间的相似程度（通过功能研究和活细胞成像）。 (3)最后，为了最大限度地理解运动轴突引导，分析和克隆这个过程中两个新发现的基因参与者至关重要，即出勤和高峰时间（通过细胞实验和分子克隆）。这些研究与人类疾病的研究直接相关，因为已知指导轴突生长和突触形成的基因与人类疾病状态和人类遗传性疾病的原因有关，并且也可能在神经损伤后的再生中发挥作用。公共健康相关性：运动轴突如何长距离无差错地导航并选择适当的突触肌肉目标尚不完全清楚。该提案旨在利用遗传学研究、活细胞成像和分子生物学研究，了解关键调节基因肌肉特异性激酶 (MuSK) 如何控制轴突寻路和突触形成。这与儿童健康和遗传性疾病的研究直接相关，因为轴突寻路和突触形成的遗传缺陷会导致诸如水平凝视麻痹伴进行性脊柱侧凸或先天性肌无力综合征等疾病。