The Role of MicroRNAs in Vertebrate Muscle Development.

描述（由申请人提供）：本项目的目标是确定肌肉特异性microRNA（miRNA）在体内调节青蛙非洲爪蟾体节和肌肉形态发生中的作用。miRNA是RNA的小的非编码序列，其通过结合特异性信使RNA并阻断其翻译来转录后调节基因。它们已被证明在胚胎发生和疾病中发挥重要作用。特别令人感兴趣的是三种肌肉特异性RNA，miR-1，miR-206和miR-133，它们在心脏和骨骼肌组织的形成和维持中起重要作用。这些miRNAs与几种不同的肌肉相关疾病有关。尽管人们对这些miRNAs在发育和疾病中的作用越来越感兴趣，但迄今为止很少进行体内研究。因此，我们的实验室已经开始使用非洲爪蟾作为我们的模型系统来研究miR-206的作用。我们的初步研究表明，miR-206在适当的时间和地点在近轴中胚层中表达，以介导肌肉发育。此外，miR-206表达的敲减会导致分割、体节形成以及肌肉细胞伸长和排列方面的显着缺陷。鉴于每种miRNA被预测调节不同的靶点，我们假设这三种miRNA在调节胚胎体节和肌肉形态发生的细胞行为中具有独特和互补的作用。 我们将使用细胞和分子方法的组合来检验这一假设：敲低每种miRNA对体节和肌肉形态发生的影响（目标1）;过表达每种miRNA对体节和肌肉形成背后的形态发生运动的影响（目标2）;以及miR-1，miR-206和miR-133对形态发生的组合作用（目标3）。总的来说，这项工作将提供一个全面的体内检查的作用，这三个miRNAs的体节和肌肉形成在胚胎发育过程中，也将确定细胞的机制，这是重要的形态学过程中，这些miRNAs的调节。 这个SC-3项目将通过与加州大学伯克利分校哈兰德实验室的持续合作进一步推动PI的发展，哈兰德实验室是一个一流的非洲爪蟾实验室，已经开发了许多尖端工具，用于研究非洲爪蟾胚胎发育过程中的基因调控。在这种合作努力和所需资金的帮助下，PI将提高她的研究生产力，以过渡到主流资金。该项目还将在全国最具文化多样性的综合性公立大学之一为大量本科生和硕士生，主要是代表性不足的少数民族，提供一个重要研究领域的研究培训机会。

DESCRIPTION (provided by applicant): The goal of this project is to determine the role that muscle-specific microRNAs (miRNA) play in vivo to regulate somite and muscle morphogenesis in the frog, Xenopus laevis. miRNAs are small, non-coding sequences of RNA that regulate genes post-transcriptionally by binding specific messenger RNA and blocking its translation. They have been shown to play a major role in embryogenesis and diseases. Of particular interest are three muscle-specific RNAs, miR-1, miR-206 and miR-133, which play an important role in the formation and maintenance of cardiac and skeletal muscle tissue. These miRNAs have been linked to several different muscle-related diseases. Although there is growing interest in the role of these miRNAs in development and disease, very few in-vivo studies have been conducted to date. Thus, our lab has begun to examine the role of miR-206 using Xenopus laevis as our model system. Our preliminary studies indicate that miR-206 is expressed in the paraxial mesoderm at the right time and place to mediate muscle development. Further, knockdown of miR-206 expression leads to significant defects in segmentation, somite formation and muscle cell elongation and alignment. Given that each miRNA is predicted to regulate different targets, we hypothesize that these three miRNAs have both unique and complementary roles in regulating the cell behaviors that underlie embryonic somite and muscle morphogenesis. We will test this hypothesis using a combination of cell and molecular approaches to examine: the impact of knocking down each miRNA on somite and muscle morphogenesis (Aim 1); the impact of overexpressing each miRNA on the morphogenetic movements underlying somite and muscle formation (Aim 2); and the combinatorial roles of miR-1, miR-206 and miR-133 on morphogenesis (Aim 3). Collectively, this work will provide a comprehensive in vivo examination of the role of these three miRNAs on somite and muscle formation during embryogenesis and will also identify cellular mechanisms that are important in this morphological process that are regulated by these miRNAs. This SC-3 project will further the PI's development through ongoing collaboration with the Harland laboratory at UC Berkeley, a premier Xenopus lab that has developed many cutting edge tools for investigating gene regulation during Xenopus embryonic development. With the help of this collaborative effort and the requested funding, the PI will increase her research productivity in order to transition to mainstream funding. The project will also provide research training opportunities in an important field of study for large numbers of undergraduate and master's students, primarily underrepresented minorities, at one of the nation's most culturally diverse comprehensive public universities.