FIG. 4.
Cell fluorescence in muscle isolates. Following 6 days in culture, fluorescence was observed in proliferating cells. (Top Row) Triculture of equal populations of tdTomato, GFP, and wild-type cells exhibited cells expressing either red, green, or no fluorescence. Fusion of red and green myoblasts into a chimeric myotube is indicated by the white arrowhead. (2nd Row) Ubiquitous red fluorescence alone was observed in cells isolated from tdTomato rats, (3rd Row) whereas only green fluorescence was present in cells from the GFP animal. Quantification of these fluorescence intensities indicated the tdTomato signal was significantly greater than the GFP signal (8.83 ± 1.51 vs. 3.22 ± 0.55, p = 0.008, n = 6). (Bottom Row) Cells isolated from wild-type animals exhibited no red or green fluorescence above background levels.