Expression of γ-globin in postnatal compound mutant mice. (A) S1 nuclease protection assay on bone marrow RNA from 5-week-old and 12-week-old mice, detecting human γ- and β-globin mRNA. Mouse α-globin was used as a loading control. For comparison, fetal liver (FL) RNA from E18.5 embryos was used. Note that the probe detecting γ-globin had a 10-fold higher specific activity than the one used in Figure 5. (B) QRT-PCR analysis of human globin expression (ct, n = 3 and Klf1^wt/ko::Bcl11a^cko/cko, n = 4 for each time point). The white circle in (A) denotes an animal heterozygous for the human β-globin locus transgene. *P < .05 between age-matched mutant and control groups. BM, bone marrow.