Functional Conservation of Myogenic Regulatory Factors

描述(由申请人提供)：该项目的长期目标是了解生肌调节因子(MRF)基因家族的功能特性。这些基因存在于从水母到人类的各种动物中，通常只在肌肉或肌肉前体细胞中活跃，在肌肉发育中发挥关键作用。MRF基因也被证明参与肌肉损伤或废弃后的修复和再生，并在某些肌肉异常和疾病状态中发挥重要作用。因此，他们的研究对人类健康问题具有明确的影响。本项目使用海鞘的胚胎作为一种简单的体内测试系统来研究MRF基因的特性。我们计划采取两种方法。一是确定已知对脊椎动物MRF活性重要的蛋白质基序是否也对Ciona MRF基因Ci-MRF的功能重要。我们将通过制造在这些基序中突变的Ci-MRF蛋白，然后检测突变蛋白刺激Ciona胚胎非肌肉细胞中肌肉发育的能力来做到这一点；以前，我们在本实验中证明了正常(即非突变)Ci-MRF蛋白刺激肌肉发育。我们的第二种方法是测试来自各种其他动物的MRF，以确定其在Ciona胚胎中指导肌肉发育的能力。在这些实验中，来自另一种动物的MRF(“异源”MRF)被引入到Ci-MRF缺陷的Ciona胚胎中，而Ciona胚胎不产生肌肉。然后，我们将确定哪些异源MRF可以挽救肌肉发育。在这两种方法中，都使用了简单、高度特异的肌肉发育和分化标记物来分析实验结果。由于海鞘是被囊动物，是脊椎动物最接近的近亲，我们的研究将提供与MRF在脊椎动物肌肉发育中的功能高度相关的见解，以及对MRF基因家族的基本特性的见解。 公共卫生相关性：该项目的目标是了解生肌调节因子(MRF)基因家族的功能。MRF基因在肌肉发育、损伤或废弃后的肌肉修复和再生以及某些肌肉异常和疾病状态中发挥关键作用。因此，了解MRF基因的特定功能对人类健康具有明显的相关性。

DESCRIPTION (provided by applicant): The long-term objective of this project is to understand the functional properties of the myogenic regulatory factor (MRF) family of genes. These genes exist in animals ranging from jellyfish to humans, and are typically active only in muscle or muscle precursor cells where they play key roles in muscle development. MRF genes have also been shown to be involved in muscle repair and regeneration following injury or disuse, and to play significant roles in certain muscle abnormalities and disease states. Thus their study has clear implications for issues of human health. This project uses embryos of the ascidian, Ciona intestinalis, as a simple in vivo test system to investigate the properties of MRF genes. We plan two approaches. One is to determine whether protein motifs known to be important for vertebrate MRF activities are also important for the function of the Ciona MRF gene, Ci-MRF. We will do this by making Ci-MRF proteins with mutations in these motifs and then assaying the mutant proteins for the ability to stimulate muscle development in non-muscle cells of Ciona embryos; previously we showed that normal (i.e. non-mutant) Ci-MRF proteins stimulated muscle development in this assay. Our second approach is to test MRFs from a wide variety of other animals for the ability to direct muscle development in Ciona embryos. In these experiments, an MRF from another animal (a "heterologous" MRF) is introduced into Ci-MRF deficient Ciona embryos, which do not make muscle. We will then determine which heterologous MRFs rescue muscle development. In both approaches simple, highly specific markers of muscle development and differentiation are used to analyze experimental outcomes. Because ascidians are tunicates, the closest living relatives of the vertebrates, our studies will provide insights that are highly relevant to the functions of MRFs in vertebrate muscle development as well as insight into the fundamental properties of the MRF gene family. Public Health Relevance: The goal of this project is to understand the functions of the myogenic regulatory factor (MRF) family of genes. MRF genes play key roles in muscle development, in muscle repair, and regeneration following injury or disuse, and in certain muscle abnormalities and disease states. Thus, understanding the specific functions of MRF genes has clear relevance for human health.