Linking motorneuron fate and connectivity in Drosophila

连接果蝇运动神经元的命运和连接

• 批准号: 7869529
• 负责人: Heather Broihier
• 金额: $ 17.78万
• 依托单位: CASE WESTERN RESERVE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-04-01 至 2011-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7869529
• 关键词: Affect; Alleles; Antibodies; Axon; Behavior; Binding; Biochemical; Biological; Biological Assay; Biological Availability; Cleaved cell; Clinical; Co-Immunoprecipitations; DNA Transposable Elements; Data; Defect; Development; Disease; Drosophila genus; Embryo; Embryonic Development; Event; Exhibits; Family; Genes; Genetic; Genetic Epistasis; Goals; Growth Factor; Human; Human Development; Individual; Insulin Signaling Pathway; Length; Link; Marfan Syndrome; Matrix Metalloproteinases; Medical; Microfibrils; Mitotic; Modeling; Molecular; Molecular Genetics; Motor; Muscle; Muscle fasciculation; Mutation; Nerve; Neurons; Paper; Pathway interactions; Pattern; Peptide Hydrolases; Phenotype; Play; Population; Process; Proteins; Publishing; RNA Interference; Regulation; Resources; Role; Signal Pathway; Signal Transduction; Stereotyping; Study Section; Testing; Western Blotting; Work; Yeasts; axon guidance; design; extracellular; falls; fibrillin; gain of function; genetic analysis; graduate student; in vivo; interest; knock-down; loss of function; mutant; neuromuscular; neuron development; novel; research study; response; transcription factor; yeast two hybrid system

Our long term aim is to use a genetic approach in Drosophila to understand molecular mechanisms of motorneuron fate specification and differentiation. In this proposal, we focus on mechanisms linking motorneuron fate to axon guidance. In a large-scale screen for mutants affecting motorneuron development, we have identified foxO and Mmp2, both of which are expressed in motorneuron subsets and necessary for proper motor axon guidance. We focus on these two evolutionarily-conserved proteins as they provide us with novel entry points for elucidating how distinct behaviors of motorneurons are developmentally regulated. Our goals here are to complete molecular, genetic, and phenotypic analyses of these genes in order to understand the observed mutant phenotypes. FoxO is a transcription factor best known for its role in the insulin signaling pathway where it is regulated by extracellular signals. Our preliminary data suggest that FoxO is expressed specifically in clusters of motorneurons in response to a target-derived signal. Detailed expression and phenotypic analyses will elucidate the role of FoxO in motorneuron development. Furthermore, we will identify the signaling pathway(s) regulating FoxO expression in motorneurons through molecular and genetic epistasis experiments. Matrix metalloproteinases (Mmps) comprise a large family of. transmembrane and secreted proteases that together cleave nearly every component of the ECM.Mmp2 is expressed in stereotyped populations of motorneurons and is necessary for proper motor axon guidance. We will characterize the expression pattern of Mmp2 in post-mitotic neurons and elucidate its role in motor axon guidance by analyzing motor axon outgrowth in Mmp2 mutant embryos. Additionally, we will establish whether Mmp2 is necessary for motor axon defasciculation by analyzing genetic interactions between Mmp2 and guidance molecules known to regulate this key pathfinding step. These studies will advance our understanding of how molecules acting in distinct motorneuron populations coordinate to establish proper patterns of neuromuscular connectivity. Motorneuron differentiation is an essential event in neuronal development and can be disrupted in human development and disease. Furthermore, since both foxO and Mmp2 are evolutionarily-conserved proteins acting in pathways of intense clinical interest, these studies should have broad biological and medical significance.

我们的长期目标是使用果蝇的遗传学方法来了解 运动神经元命运的规范和区分。在本提案中，我们将重点放在机制链接上 运动神经元的命运指向轴突引导。在大规模筛选影响运动神经元发育的突变体中， 我们已经鉴定出FOXO和MMP2，这两个基因都在运动神经元亚群中表达，是 正确的运动轴突导引。我们专注于这两个进化上保守的蛋白质，因为它们为我们提供了 以新的切入点阐明运动神经元的不同行为是如何发育调节的。 我们的目标是完成这些基因的分子、遗传和表型分析，以便 了解观察到的突变表型。FOXO是一种转录因子，最为人所知的是它在 受细胞外信号调节的胰岛素信号通路。我们的初步数据表明 FOXO在运动神经元簇中特异性地表达，对靶信号做出反应。详细 表达和表型分析将阐明FoxO在运动神经元发育中的作用。 此外，我们还将确定调控运动神经元FoxO表达的信号通路(S)，通过 分子和遗传上位性实验。基质金属蛋白酶(MMPs)是一大家族。 Mmp2是一种跨膜和分泌的酶，它们共同切割ECM的几乎每一个成分。 在固定的运动神经元群体中表达，是正确的运动轴突导引所必需的。 我们将描述MMP2在有丝分裂后神经元中的表达模式，并阐明其在运动中的作用 通过分析MMP2突变胚胎中运动性轴突的生长来指导轴突生长。此外，我们还将建立 通过分析MMP2之间的遗传交互作用探讨MMP2是否对运动轴突除鞭作用是必需的 以及已知的调节这一关键探路步骤的引导分子。这些研究将推动我们的 理解作用于不同运动神经元群体的分子如何协调以建立适当的 神经肌肉连接的模式。运动神经元分化是神经细胞发生的重要事件 在人类发展和疾病方面可能会受到干扰。此外，由于FOXO和 这些研究表明，MMP2是进化上保守的蛋白质，在具有强烈临床意义的通路中发挥作用。 应该具有广泛的生物学和医学意义。