Relative preservation of KSL phenotype by constitutive expression of HES-1.

(A) Colony-forming ability of transduced cells was examined soon after sorting GFP⁺ cells and after an additional 3-day culture. HPP-mix; colonies larger than 1.5 mm in diameter and consisting of at least granulocyte/macrophage and erythroid clusters. The number of HPP-mix–derived colonies in 1000 cells (culture day 2; sort day 0) or 2000 cells (culture day 5; sort day 3) is shown. Data show the mean ± SD of triplicates from 2 independent experiments. (B) Long-term repopulation ability of selected transduced cells was assessed by transplantation to sublethally irradiated recipients. Donor (GFP⁺Ly5.1⁺)–derived cells were detected in peripheral blood of recipient mice (Ly5.2). The percentage of donor-derived cells within myeloid (Mac-1⁺ and Gr-1⁺) and lymphoid (Thy1.2⁺ and B220⁺) cells was measured at various time points after transplantation. Results for HES-1IGv and GFPv are shown as the mean ± SD of 12 and 9 measurements, respectively, from 3 independent experiments (2-6 animals per experiment).