Identification of Mechanisms Regulating Muscle Size and Shape

调节肌肉大小和形状的机制的识别

• 批准号: 8040998
• 负责人: Krista Carol Dobi
• 金额: $ 5.47万
• 依托单位: SLOAN-KETTERING INST CAN RESEARCH
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-04-01 至 2012-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8040998
• 关键词: Actins; Adopted; Affect; Behavior; Biological Models; Cell Adhesion; Cell Shape; Cell physiology; Cells; Cellular biology; Confocal Microscopy; Data; Development; Differentiated Gene; Disease; Dorsal; Drosophila genus; Drosophila melanogaster; Embryo; Etiology; Fluorescence; Fluorescence-Activated Cell Sorting; Gene Expression; Gene Targeting; Genes; Genetic; Genetic Epistasis; Genome; Genomics; Goals; Homeobox; Image; Individual; Knowledge; Lateral; Lead; Life; Location; Microarray Analysis; Microscopy; Microtubules; Molecular; Morphogenesis; Morphology; Muscle; Muscle Development; Muscle Fibers; Muscular Dystrophies; Myoblasts; Pattern; Phenotype; Physiology; Positioning Attribute; Predisposition; Process; Property; Relative (related person); Research; Rhabdomyosarcoma; Role; Running; Shapes; Site; Skeletal Muscle; Specific qualifier value; Tendon structure; Testing; To specify; Transgenes; Translating; Translations; Work; gain of function; insight; interest; loss of function; loss of function mutation; mutant; myogenesis; repaired; research study; stem cell differentiation; success; tissue regeneration; tool; transcription factor; wasting

DESCRIPTION (provided by applicant): From the muscles allowing people to run to those that direct the blink of an eye, skeletal muscles come in a variety of shapes and sizes. These muscles have different functions; additionally, they also have different susceptibilities to diseases like muscular dystrophy and rhabdomyosarcoma. Since potential therapies to repair muscle wasting will require the ability to generate muscles of a specific size and shape, an important step in developing treatments will be to understand how muscle diversity is achieved. In the fruit fly Drosophila melanogaster, a group of transcription factors, known as identity genes, mark subsets of muscles and are important for their morphology. Few downstream targets of these transcription factors are known, however, and little is known about how identity genes control muscle diversity. The goal of this proposal is to determine how morphological information is translated from the identity genes to the cellular processes that control muscle size and shape. The central hypothesis of this research is that identity genes work in combination with each other to direct muscle morphogenesis by regulating cytoskeletal remodeling, cell adhesion and myoblast fusion, among other cellular behaviors. The morphogenesis of the lateral transverse (LT) muscles of the Drosophila embryo will be analyzed using mutant analysis, live imaging, and genomic approaches to identify factors regulating the development of those muscles. The focus of these experiments will be to determine how identity genes work in combination to direct LT muscle morphology. Five identity genes have been shown to be expressed in and affect morphogenesis of the LT muscles: Kruppel, twist, apterous, muscle segment homeobox and caupolican. Mutants for each of these genes will be examined to determine the relative contributions of each identity gene to the final muscle morphology, as well as to determine the genetic hierarchy beteween these five transcription factors. Morphogenesis will be characterized by live confocal imaging of fluorescent markers, elucidating the steps in this process and aiding in the interpretation of genetic data. Finally, fluorescence activated cell sorting (FACS) will be used to isolate subpopulations of myoblasts from Drosophila embryos; microarray analysis will be performed on particular groups of cells to identify the targets of identity genes within the developing muscles. We will focus further studies on those genes predicted to have roles in cell shape or tendon attachment. Taken together, these data will provide insight to the mechanisms by which identity genes act together to specify a muscle's unique size and shape.

描述(申请人提供)：从允许人们奔跑的肌肉到指导眨眼的肌肉，骨骼肌有各种形状和大小。这些肌肉具有不同的功能；此外，它们对肌肉营养不良和横纹肌肉瘤等疾病的易感性也不同。由于修复肌肉萎缩的潜在疗法将需要产生特定大小和形状的肌肉的能力，因此开发治疗方法的重要一步将是了解肌肉多样性是如何实现的。在果蝇黑腹果蝇中，一组被称为身份基因的转录因子标记肌肉的亚群，对它们的形态很重要。然而，这些转录因子的下游靶标知之甚少，关于身份基因如何控制肌肉多样性也知之甚少。这项提议的目标是确定形态信息如何从身份基因转换到控制肌肉大小和形状的细胞过程。这项研究的中心假设是，身份基因相互结合，通过调节细胞骨架重塑、细胞黏附和成肌细胞融合等细胞行为来指导肌肉形态发生。将使用突变分析、活体成像和基因组方法分析果蝇胚胎外侧横肌的形态发生，以确定调控这些肌肉发育的因素。这些实验的重点将是确定身份基因如何结合在一起指导LT肌肉的形态。已有研究表明，5个同源基因在LT肌中表达并影响其形态发生：Kruppel、Twist、Apterous、肌肉节段同源盒和caupolcan。每个基因的突变体将被检查，以确定每个身份基因对最终肌肉形态的相对贡献，以及确定这五个转录因子之间的遗传等级。形态发生的特征将是荧光标记的实时共聚焦成像，阐明这一过程中的步骤，并帮助解释遗传数据。最后，将使用荧光激活细胞分类(FACS)从果蝇胚胎中分离成肌细胞亚群；将对特定的细胞组进行微阵列分析，以确定发育中肌肉中特定基因的靶标。我们将把重点放在那些预测对细胞形状或肌腱附着有作用的基因上。综上所述，这些数据将提供对身份基因共同作用以指定肌肉独特大小和形状的机制的洞察。