Figure 1.

c-Myb hemizygous bone marrow cells are less efficiently transformed by the p190^BCR/ABL oncogene. (A) Infiltration of p190^BCR/ABL-transduced Myb^f/f and Myb^f/d bone marrow cells into bone marrow and spleen of lethally-irradiated recipient mice. GFP expression from the MigRI/GFP bicistronic retrovirus was used to detect BCR/ABL-expressing donor cells. Recipient mice were sacrificed 8 weeks after transplantation with 2×10⁶ MigRI p190^BCR/ABL-transduced bone marrow cells. GFP⁺ cells were detected by flow cytometry; inset shows that nearly all GFP⁺ cells were CD19⁺; (B) Different numbers of CD19⁺CD43⁺ GFP⁺ cells (inset) from mice transplanted with p190BCR/ABL-transduced Myb^f/f marrow cells were injected into sub-lethally-irradiated secondary recipient mice and GFP-positive cells analyzed by flow cytometry in bone marrow and spleen once moribund mice were sacrificed (2–3 weeks post-injection). (C) Kaplan-Meier plot shows survival of mice injected with 2 × 10⁶ p190^BCR/ABL-transduced Myb^f/f or Myb^f/d bone marrow cells transduced with p190^BCR/ABL alone with p190^BCR/ABL and Δ(358–452) c-Myb. (D) Representative immunophenotype of GFP⁺ cells from bone marrow and spleen of mice injected with p190^BCR/ABL-transduced Myb^f/f cells [CD19⁺CD43⁺ (top panel); CD19⁺IgM⁺ (bottom panel)].