Donor-derived chimerism in the peripheral blood and BM of NSG recipients that received transplantation with the indicated number of tdTomato⁺ or tdTomato⁻ Lin^loKit⁺ HSPCs from Ai9;SpCas9-EGFP animals previously injected with 5 × 10¹² vg per animal scAAV encoding targeting gRNAs. Donors are grouped into equal donor cell number (at ∼7000 donor cells) tdTomato⁺ or tdTomato⁻ source; the “high donor number” condition, averaging 20 000 donor cells (for tdTomato⁻ donor source only), was included to provide functional assessment of the higher frequency of phenotypic HSCs in tdTomato⁺ Lin^loKit⁺, compared with tdTomato⁻ counterparts (Figure 2B). Blood chimerism 12 weeks after transplant is shown for the following populations: total (CD45⁺), B cell (B220⁺), T cell (CD3⁺), macrophage (CD3⁻B220⁻CD11b⁺), granulocyte (CD3⁻B220⁻CD11b⁺Gr1⁺). Percent donor-derived HSPCs (Lin^loKit⁺CD150⁺CD48⁻) is also shown for individual animals. “Successful engraftment” is determined as outlined in supplemental Methods and displayed in bold font.

nd, not determined.