HbF reactivation in sibling BFU-E colonies.
(A) Top: Percentage of F cells evaluated in single sibling BFU-E colonies grown in unilineage erythroid cultures supplemented with KL ± Dex at 3 different concentrations (10−9, 10−8, or 10−7 M). Results from 9 experiments, each including 4 sibling colonies each represented by the same symbol (mean values are also indicated). P < .01 when comparing the 10−8 M and 10−7 M Dex groups with the control group. Bottom: Percentage of γ-globin chains evaluated by HPLC in the unicellular sibling BFU-E cultures. Results from 5 experiments, each including 4 sibling colonies.P < .01 when comparing the 10−8 M and 10−7 M Dex groups with the control group. (B) Top: Single values of cell number/colony from 12 different clones, each including 4 sibling BFU-E colonies, grown as described above (mean values are also indicated). Bottom: Direct correlation between F-cell frequency (percentage values) and cell number × 103 in 36 sibling colonies (P < .001).
