Meeting Abstract

P1.134  Monday, Jan. 4  Characterization of Novel Teleost Systems for Studying Muscle Growth FROEHLICH, J.M.*; BIGA, P.R.; North Dakota State University; North Dakota State University jacob.froehlich@ndsu.edu

The zebrafish (Danio rerio) is an extensively used model organism in biomedical research. However, zebrafish exhibit a pattern of determinate muscle growth, limiting its usefulness into investigations of satellite cell activation. A closely related species, the giant danio (D. aequipinnatus), exhibits indeterminate muscle growth, which is similar to commercially important teleost species like the rainbow trout (Oncorhynchus mykiss). Here, we characterize satellite cells isolated from giant danio and rainbow trout, as well as the subsequent in vitro activation, differentiation, and proliferation of the resulting primary myoblasts. Cells were cultured for 15 days, with sampling occurring throughout the culture period. Quantitative PCR was utilized to analyze the gene expression of c-Met, Pax7, Foxk1, MyoD, myogenin and Myf5 to demonstrate cell proliferative or differentiation stages. Throughout the 15 days of culture, MyoD was present, while myogenin appeared only after the second day of culture, indicating the start of myoblast proliferation. Myf5 was detected at all sampling days, which is indicative of myofiber differentiation and growth. Foxk1 mRNA levels appeared to be highest on day 1 of culture, with a subsequent down-regulation as cells proliferate and differentiate. Pax7b and c-Met were detected throughout the culture. The presence of Foxk1, Pax7b and c-Met throughout the entire culture suggests that a replenishment of the satellite cell population might be occurring. This is the first report of myocyte-specific cell stage markers in teleost primary myoblast culture systems and supports the use of these systems in subsequent work evaluating satellite cell activation and muscle cell growth regulation. Funded by ND EPSCoR #0447679 and NIH NCRR #2P20RR015566.