Clock1a 基因在鳜鱼肌肉节律性表达的分子机制及功能研究

Biorhythm is the most common phenomenon of physiology in vertebrates, as well as in fish, and it is regulated by clock genes. The Mandarin fish has been considered as one of the most precious species and it has now become a popular cultured species in our country. In this proposal,we will use the mandarin fish as a model to identify its clock1a gene and to investigate its daily gene expression in fast skeletal muscle with the techniques of both cDNA cloning, real-time PCR. In the meantime,we will analyze the temporal and spatial expression characteristics of clock1a gene in Mandarin fish embryos and tissue with real-time PCR and in situ hybridization. Further, we will apply both the gene knockdown and overexpression technologies to investigate the clock1a gene’s function and its influences on the expression of myogenic regulatory factors and mucscle developement. The obtained results from this study will not only allow us to better understanding the rhythmic expression of clock1a gene in the fish skeletal muscle and its function in muscle developement, but also they have practical implication in improvement in aquacluture.

生物节律是动物包括鱼类中最常见的生理学现象，受到生物钟基因clock的调控。本研究拟选用我国重要经济名贵鱼类—鳜鱼为研究对象，在克隆其clock1a基因cDNA序列的基础上，采用定量PCR技术对该基因在肌肉中的节律性表达进行分析，同时采用qRT-PCR 和原位杂交技术研究该基因的时空表达规律，以阐明鳜鱼重要节律基因clock1a的基因结构和表达特征。进而，通过基因敲低和过表达技术分析clock1a基因对其下游钟控的生肌调节因子家族基因的调控机制及对肌肉分化发育的影响，从而揭示该基因的生物学功能和作用机理。本研究成果既具有重要的鱼类发育分子生物学的理论意义，又具有指导渔业生产的潜在应用价值。

Clock 基因是调控多种生物包括鱼类生物节律的核心生物钟基因之一。本研究以具有优良肉质性状的名贵鱼类—鳜鱼为研究对象，克隆得到了包括鳜鱼 clock1a 基因（即 clock基因）在内的5个生物钟相关基因全序列；分析了clock 基因在成体鳜鱼多种不同组织中的表达规律；研究了经模拟光周期处理后，成年鳜肝脏、心脏、快肌、慢肌组织中包括 clock 基因在内的十余个生物钟相关基因及肝脏、心脏、肌肉重要功能基因的昼夜表达节律性及其相关性；初步构建了鳜鱼快、慢肌中节律性表达的生物钟基因及下游钟控重要肌肉功能基因的调控关系图谱。研究结果有助于进一步阐明生物钟基因及下游钟控肌肉功能基因对鳜鱼的肌肉发育和生物钟系统节律性的协同调控机理，同时为鱼类高效健康养殖提供理论和技术支撑。