Fig. 3

Enhanced transfection efficieny of the chondrocyte-like immortalized zebra finch cell line. A Representative images of transfected immortalized cells and primary zebra finch embryonic fibroblasts (ZEFs). Scale bar, 100 μm. B Transfection efficiencies of the primary and immortalized cells, as determined by flow cytometry. C The viabilities of the transfected primary and immortalized cells, determined via manual counting after trypan blue staining; ***p < 0.0001. D The sensitivity of chondrocyte-like zebra finch immortalized cells to G418. The cells were exposed to increasing concentrations of G418 for 1 week and the percentage survival was determined by trypan blue staining. E Schematic overview of the piggyBac YFP expression plasmid and the CAGG PBase plasmid. F Images of YFP-expressing immortalized cells before and after selection with G418 (300 μg/mL). Scale bar, 100 μm. G The percentages of YFP-expressing immortalized cells before and after G418 selection; ****p < 0.0001