The cloning of zebrafish (Danio rerio)myosin heavy chain partial cDNA and the analysis of its mRNA expression pattern during development

• Main Authors: Peng, Mou-Yung, 彭僈芸
• Other Authors: Ching-Ming Kuo
• Format: Others
• Language: zh-TW
• Published: 1998
• Online Access: http://ndltd.ncl.edu.tw/handle/63589704183097932902

碩士 === 國立臺灣大學 === 漁業科學研究所 === 86 === The first somite appears at 10 hr post-fertilization during zebrafish embryonic development. Somites, derived from paraxial mesoderm, differentiate into muscle, cartilage and dermis in the course of development. Myosin, one of the main muscular structural proteins, primarily functions as the source of contraction force for muscle movement. Approximately 14 classes of myosin molecules have been identified from diverse organisms. For example, myosin II is consisted of two identical heavy chains and four different light chain subunits. A 2 kb cDNA was cloned from agt10 cDNA library, which was obtained from poly(A)+ mRNA in one-month old zebrafish larvae. Nucleic acid and deduced amino acid sequence analyses showed that the 2 kb cDNA shared high similarity with that of fast skeletal muscle myosin heavy chain from carp (Cyprinus carpio). They shared 76% nucleic acid sequence identity, 83.5 % amino acid sequence identity, and 88% amino acid sequence similarity. The expression of myosin heavy chain mRNA during zebrafish development was analyzed by Northern blotting. Expression of a 6.5 kb mRNA was maximal at the time of hatching and then decreased as the development proceeds, from larval to adult stage. Whole mount in situ hybridization showed that myosin heavy chain mRNA were localized at somite region of pharyngula stage embryos and skeletal muscle region of hatching larvae, at the pectoral fins of 4-days old hatching larvae. Furthermore, results from whole mount in situ hybridization also revealed that myosin heavy chain mRNA were mainly expressed in the fast muscle fibers, which are believed to be the primary production sites of contraction force of embryos at hatching.