KLF7 overexpression inhibits bone marrow reconstitution. (A) Bone marrow cells transduced with MSCV expressing KLF7 or vector alone were transplanted into lethally irradiated recipients, and peripheral blood was analyzed 6 and 12 weeks after transplantation. Transduction efficiency was determined by measuring the percentage of GFP⁺ KLS cells just before transplantation (72 hours after viral exposure, time = 0). Data represent 2 individual experiments with 3-5 mice per genotype per experiment. *P < .001. (B) Shown is the percentage of donor B cells (B220⁺), T cells (CD3e⁺), and neutrophils (Gr-1 high) that were GFP⁺ from 1 representative experiment. *P < .01. (C) Bone marrow cells were transduced with HIV-MND–expressing KLF7 or vector alone at a low multiplicity of infection were transplanted into irradiated congenic recipients and the percentage GFP⁺ leukocytes in the blood measured. Data represent 3 independent experiments. *P < .001. **P < .05. (D) The percentage of donor B cells (B220⁺), T cells (CD3e⁺), and neutrophils (Gr-1 high) that were GFP⁺ at 6 weeks after transplantation. *P < .05. **P < .01. ***P < .0001. (E) GFP⁺ cells were sorted 72 hours after viral transduction and RNA analyzed by real-time RT-PCR for KLF7 expression. Data are normalized to β-actin and represent 2 independent experiments. *P = .043. (F) To assess homing, GFP⁺ KLS cells were transplanted into irradiated recipients and the number of GFP⁺ cells recovered from the bone marrow 20 hours later determined. Shown are the number of GFP⁺ cells per 10⁶ whole bone marrow cells, corrected for the number of cells injected. Data represent 3 individual experiments, with 3-6 mice per condition.