Characterization of the G-CSF responsiveness of myeloid 32D cells expressing wt or EGFP-fused wt G-CSF-R. (A) Cell proliferation of individual 32D.cl8.6 clones expressing wt G-CSF-R (closed symbols) or wt G-CSF-R/EGFP (open symbols). Graphs are from independent clones. (B) Maturation of 32D.cl8.6 clones of panel A expressed as the percentage of neutrophils within the living cell population. (C) EMSA showing kinetics of STAT3 and STAT5 activation in 32D clones expressing wt G-CSF-R or wt G-CSF-R/EGFP. Cells were serum starved for 4 hours, stimulated with G-CSF for 0, 15, 30, or 60 minutes, and assayed by EMSA using m67 (STAT3) and β-cas (STAT5) probes. The upper band in the STAT3 EMSA represents STAT3/STAT3, the middle band STAT1/STAT3, and the lowest (weak) band STAT1/STAT1 complexes. Data are representative of 3 independent experiments with different cell clones.