Expression of the mLARβΔγV5 γ-globin vector in multiple isolates of a 2-copy clone is less susceptible to variegating position effects. (A) Southern blot analysis of DNAs from d432βΔγm and mLARβΔγV5 clones. DNAs were digested with BsrGI or HincII as indicated, liberating a viral vector–genomic DNA junction fragment. The lane numbers represent clone numbers, M represents lanes containing the molecular weight marker, and Mo indicates a sample from a mock-transduced CFU-S isolate. (B) The percentage of HbF+ cells as determined by FACS analysis is shown for each isolate of the indicated d432βΔγm G and mLARβΔγV5 D clones. The mean ± SEM of HbF+ cells for each group is shown, with the mean indicated by the solid horizontal bar. The P value indicates a statistically significant difference between the mean values of the 2 groups. (C) The MFI of staining with the HbF monoclonal antibody is shown for the different d432βΔγm clone G and mLARβΔγV5 clone D isolates. The mean ± SEM MFI values for each group are shown, with the horizontal solid bar indicating the mean value for each group of clones. The P value indicates a statistically significant difference between the mean values of the 2 groups.
