Genetic analysis of FRG1 function in Drosophila

果蝇FRG1功能的遗传分析

• 批准号: 7848533
• 负责人: WILLIAM W MATTOX
• 金额: $ 1.79万
• 依托单位: UNIVERSITY OF TX MD ANDERSON CAN CTR
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-07-01 至 2009-10-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7848533
• 关键词: 4q35; Adult; Affect; Animal Model; Attention; Biochemical; Biochemical Pathway; Biochemistry; Biological Assay; Biological Models; Cell physiology; Collection; Complement; Complex; DNA Sequence Rearrangement; Degenerative Disorder; Development; Disease; Drosophila genus; Drosophila melanogaster; Eye; Facioscapulohumeral Muscular Dystrophy; Future; Genes; Genetic; Genetic Screening; Genetic Transcription; Goals; Histology; Homologous Gene; Human; In Vitro; Knowledge; Laboratories; Lesion; Link; Modeling; Molecular; Molecular Genetics; Molecular Target; Morphology; Muscle; Muscle function; Mutation; Nuclear Extract; Organism; Pathway interactions; Phenotype; Physiological; Play; Population; Positioning Attribute; RNA Splicing; Role; Spliceosomes; Symptoms; Syndrome; System; Testing; Therapeutic; Therapeutic Intervention; Tissues; Transgenes; Transgenic Mice; Transgenic Organisms; Work; base; compound eye; experience; fly; gene function; genetic analysis; mRNA Precursor; mouse model; novel; overexpression; wasting

DESCRIPTION (provided by applicant): Facioscapulohumeral muscular dystrophy (FSHD) is a progressively debilitating syndrome that is the nation's third most common type of dystrophy, yet the development of directed therapies remains hampered by our poor understanding of its molecular basis. Recent progress using a mouse model system suggests that overexpression of the FRG1 gene is sufficient to cause a number of FSHD symptoms. Thus a promising avenue for therapeutic intervention is the reduction of FRG1 expression and/or function. Several lines of evidence suggest that FRG1 associates with the RNA splicing machinery and may alter normal splicing when overexpressed, but the specific biochemical activity of FRG1 remains unknown. In this project we will utilize the powerful genetic approaches available in the fruitfly Drosophila melanogaster to identify molecular pathways through which FRG1 functions. Using the GAL4-UAS system we will target overexpression of FRG1 specifically to the indirect flight muscle of the adult fly. The morphology and function of this muscle are easily assessed and it therefore an ideal target for genetic studies. Because FSHD has a variety of extramuscular effects we will also examine the effects of FRG1 overexpression on the Drosophila compound eye, a highly ordered tissue that is frequently exploited for analysis of gene function. Using overexpression phenotypes in these tissues we will carry out genetic screens to identify modifier mutations that reverse the harmful effects of excess FRG1 expression. Because such screens are carried out in unbiased manner they offer the potential to identify novel interacting factors that would not otherwise have been considered or investigated. As no specific biochemical activity has previously been linked with FSHD, these factors will provide new targets for strategies aimed at therapeutic inhibition of FRG1 function. In parallel studies we will exploit the extensive knowledge of RNA splicing mechanisms already developed in Drosophila to ask whether FRG1 is a required component of the spliceosome. Using an in vitro splicing system we will identify the specific steps in splicing and splicing complex assembly and function where FRG1 acts. These studies will thus provide the first genetic and biochemical analysis of FRG1 in Drosophila. By developing Drosophila as a model for FSHD this work will form a basis for future studies that will elaborate a detailed understanding of both the normal molecular function of FRG1 and the effects of its overexpression in muscle. These studies thus offer the potential to uncover novel biochemical pathways that affect muscle function and disease.

描述（由申请人提供）：面肩肱型肌营养不良症（FSHD）是一种进行性衰弱综合征，是美国第三大常见的营养不良类型，但由于我们对其分子基础了解甚少，定向疗法的发展仍然受到阻碍。最近使用小鼠模型系统取得的进展表明，FRG1 基因的过度表达足以引起许多 FSHD 症状。因此，治疗干预的一个有希望的途径是减少 FRG1 表达和/或功能。多项证据表明，FRG1 与 RNA 剪接机制相关，并且在过度表达时可能会改变正常剪接，但 FRG1 的具体生化活性仍不清楚。在这个项目中，我们将利用果蝇中可用的强大遗传方法来识别 FRG1 发挥作用的分子途径。使用 GAL4-UAS 系统，我们将 FRG1 的过度表达专门针对成年果蝇的间接飞行肌。这种肌肉的形态和功能很容易评估，因此它是遗传学研究的理想目标。由于 FSHD 具有多种肌外效应，我们还将检查 FRG1 过度表达对果蝇复眼的影响，果蝇复眼是一种高度有序的组织，经常用于分析基因功能。利用这些组织中的过度表达表型，我们将进行遗传筛选，以确定可逆转 FRG1 过度表达的有害影响的修饰突变。由于此类筛选是以公正的方式进行的，因此它们提供了识别新的相互作用因素的潜力，而这些因素原本不会被考虑或研究。由于之前没有与 FSHD 相关的特定生化活性，这些因素将为旨在治疗性抑制 FRG1 功能的策略提供新的靶点。在平行研究中，我们将利用果蝇中已经开发的 RNA 剪接机制的广泛知识来询问 FRG1 是否是剪接体的必需成分。使用体外剪接系统，我们将确定剪接以及剪接复杂组装和 FRG1 发挥作用的功能的具体步骤。因此，这些研究将首次对果蝇中的 FRG1 进行遗传和生化分析。通过将果蝇开发为 FSHD 模型，这项工作将为未来的研究奠定基础，这些研究将详细了解 FRG1 的正常分子功能及其在肌肉中过度表达的影响。因此，这些研究提供了揭示影响肌肉功能和疾病的新生化途径的潜力。