Discussion

The addition of FgF2 showed an almost 10 fold decrease with increasing concentrations, in the number of myoblasts. Myosin positive cells showed morphological differences as well. We conclude, therefore, that the myosin positive cells did not reach the second and third stages of muscle differentiation. This might be attributed to the inability of a fibronectin-integrin attachment. The cells that were in cluster bundles, were not committed myoblasts. The only committed cells were isolated from other cells. Although the results were limited, we conclude that FgF2 was an inhibitory molecule acting on muscle differentiation.
Numerous difficulties were encountered throughout this experiment. Few cells adhered to the plates due to small amounts of gelatin binding to the wells. In addition, a low plating efficiency makes it difficult to determine if fibronectin was secreted by the cells (late stage one of muscle development). The fact that the cells did not differentiate into the muscle can be attributed to the distance between the cells which would not allow them to adhere through integrin-fibronectin attachment. In future experiments, we would stain (with immunostaining) for fibronectin to determine if cells were secreting the protein.