Functional Conservation of Myogenic Regulatory Factors

描述（由申请人提供）：本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用后的修复和再生，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有明确的意义。本计画利用海鞘玻璃海鞘的胚胎，作为一个简单的活体测试系统来研究MRF基因的特性。我们计划两种方法。一个是确定已知对脊椎动物MRF活性重要的蛋白质基序是否对玻璃海鞘MRF基因Ci-MRF的功能也很重要。我们将通过在这些基序中制造具有突变的Ci-MRF蛋白质，然后测定突变蛋白质刺激玻璃海鞘胚胎的非肌肉细胞中肌肉发育的能力来做到这一点;先前我们在该测定中显示正常（即非突变）Ci-MRF蛋白质刺激肌肉发育。我们的第二种方法是测试来自各种其他动物的MRF在玻璃海鞘胚胎中指导肌肉发育的能力。在这些实验中，将来自另一动物的MRF（“异源”MRF）引入Ci-MRF缺陷的玻璃海鞘胚胎中，其不产生肌肉。然后，我们将确定哪些异源MRF拯救肌肉发育。在这两种方法中，肌肉发育和分化的简单，高度特异性的标志物被用来分析实验结果。由于海鞘是被囊类动物，脊椎动物的近亲，我们的研究将提供见解，是高度相关的功能MRF在脊椎动物肌肉发育以及洞察MRF基因家族的基本特性。 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、肌肉损伤或废用后的修复和再生以及某些肌肉异常和疾病状态中起关键作用。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.