Rescue of Hoxa^−/− HSC engraftment by overexpression of Hoxa9. (A) Average kinetics of engraftment in mice receiving 0.2 × 10⁶ of either control Hoxa^+/+ + GFP (n = 13), Hoxa^−/− + GFP (n = 5), and Hoxa^−/− + Hoxa9-GFP (n = 6) BM cells. Percentage of donor cells are measured by flow cytometry for GFP⁺ in the PB at indicated times. (B) LT engraftment of HSCs with indicated genotype in PB of individual mice 16 weeks posttransplantation. (C) Bar graphs depicting percentage of Hoxa^+/+ + GFP and Hoxa^−/− + Hoxa9 CD150⁺/CD48⁻/LKS HSCs (n = 3) and CD150⁻/CD48⁻/LKS MPPs (n = 3) in GFP⁺ cell population. (D) Percentage of Hoxa^+/+ + GFP and Hoxa^−/− + Hoxa9-derived B cells (B220⁺), T cells (CD3⁺), myeloid cells (Mac1⁺), and erythroid cells (Ter119⁺) in the PB of individual mice 16 weeks posttransplantation. (E-F) Percentage of B cells (B220⁺) (E) and myeloid cells (Mac1⁺) (F) of GFP⁺ cells in BM and spleen. (G) Gene expression analysis in RNASeq HSC and Lin⁻ cells overexpressing Hoxa9. ○ indicates quantity not sufficient defined as corrected CT value >36. *P < .05; ***P < .001. N.S., non-significant; MPP, multipotent progenitors; Q-RT-PCR, quantitative-reverse transcription-polymerase chain reaction; Spl, spleen.