Noncompetitive transplantation of Notch-activated HSPCs leads to hematopoietic failure. (A) Lethally irradiated CD45.1⁺ congenic mice were reconstituted with 5-FU–treated donor CD45.2⁺Rag1^−/− BM cells transduced with MigR1 control or activated Notch1. At 6 weeks after transplantation, CD45.2⁺GFP⁺Lineage⁻Sca-1⁺c-Kit⁺ cells (HSPCs) were sorted and transplanted into CD45.1⁺ hosts at 500 cells per mouse. (B) Kaplan-Meier graph showing the proportion of mice alive after transplantation. (C) Scatter plot analysis of moribund mice at 11 days after transplantation showing peripheral blood hemoglobin concentration; absolute numbers of total donor-derived (CD45.2⁺GFP⁺) splenocytes, splenic ter119⁺ erythroid cells, splenic CD11b⁺ myeloid cells, Thy-1⁺ T cells, splenic Lineage⁻Sca-1⁺c-Kit⁺ HSPCs, and splenic Lineage⁻Sca-1⁻c-Kit⁺CD34⁺CD16/62^hi granulocyte-macrophage progenitors (GMPs); and day 11 CFU-S colonies. The experiment was performed twice; 4 mice for MigR1 and 9 mice for activated Notch1.