Cloning, expression and functional characterization of prepared bovine, salmon, and cod basic fibroblast growth factor-2.

Growth factors (GFs) contribute to over 90% of the total expenses of medium costs. In this study, a codon-optimized gene encoding bovine, salmon, and cod FGF-2 was cloned into an E. coli expression vector. The bioactivity of the recombinant FGF-2 was tested in serum-free medium, demonstrating its ability to support MuSC proliferation and signaling pathways, ERK, and p38. Using serum-free medium with fetuin and Insulin-Transferrin-Selenium (ITS), all three in-house-produced recombinant FGF-2 variants showed positive effects on MuSC proliferation. Notably, bovine FGF-2 performed better using low concentrations (2 ng/mL) than the salmon and cod FGF-2, which required higher concentrations (17.5-70 ng/mL) to achieve the same effect on the cells. A synergistic relationship between bovine FGF-2 and the p38 inhibitor was revealed. These findings suggest that the medium cost from FGF-2 can be significantly reduced with optimized production and application strategies, supporting the large-scale viability of CM production.