Title: SEQUENCE, CONSERVATION, AND QUANTITATIVE EXPRESSION OF RAINBOW TROUT MYF5 Authors
Submitted to: Comparative Biochemistry and Physiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 19, 2004
Publication Date: April 1, 2005
Citation: Oveturf, K.E. and Johansen, K. 2005. Sequence, conservation, and quantitative expression of rainbow trout myf5. Comparative Biochemistry and Physiology. Interpretive Summary: Manuscript title: Sequence, conservation, and quantitative expression of rainbow trout Myf5 The successful production of rainbow trout as an aquaculture species relies on the ability to raise the fish with large amounts of high quality lean muscle. This ability will be aided by an understanding of the molecular control of muscle growth. Vertebrate muscle growth is a sequential process of cell specification, growth, and coordination, controlled by a family of four transcription factors. The sequence of two of the four transcription factors is known, and the sequence and expression pattern of a third, called Myf5, is presented here. Myf5 shows homology to the other transcription factors in the family, and based on its expression pattern, most likely has the same function. There are differences in muscle growth between fish and mammals, and it is important that the molecular control be studied in fish that are economically valuable such as rainbow trout.
Technical Abstract: Manuscript Title - Sequence, conservation, and quantitative expression of rainbow trout Myf5 The success of rainbow trout as an aquaculture species is dependent on the ability to produce fish with large amounts of high quality lean muscle. It is therefore important to understand not only the best conditions under which to raise the fish, but also the molecular control of muscle growth. Vertebrate muscle growth is initiated by the specification of myogenic precursor cells into myoblasts. The myoblasts proliferate and fuse to form multi-nucleated myotubes, which mature into myofibers. A family of bHLH transcription factors, the MRFs (Myogenic Regulatory Factors), controls these events. In trout, two MRF-encoding genes, TMyoD (of which there are two), and Tmyogenin, have been identified. However, the primary MRF-encoding Myf5 is not yet sequenced. Here, using degenerate PCR and 5’ and 3’ RACE, the cDNA sequence of trout Myf5 (TMyf5) is identified. Translation of the cDNA reveals that TMyf5 is a bHLH protein with homology to Myf5 and MRFs in other organisms. It is expressed mainly in red and white muscle, suggesting that it shares functional homology to Myf5 in other species. The molecular control of muscle growth has been well-characterized in mammals, but there are differences in the growth of fish muscle, highlighting the need for characterization of MRFs in fish species, particularly those in which understanding muscle growth will have a positive impact on the economic potential of the species.