Transplantation of Gfi1b-deficient bone marrow. (A) About 20 000 bone marrow cells of pIpC-treated Gfi1b^fl/fl and MxCre tg Gfi1b^fl/fl mice were seeded on methylcellulose. After the indicated time periods (10 days), number of colonies was determined, cells were resuspended, and 10 000 cells of the suspension were replated (n = 6). Cell numbers were analyzed at indicated time points. (B) Scheme depicting the transplantation of equal number of bone marrow cells. About 200 000 bone marrow cells from pIpC-treated Gfi1b^fl/fl or MxCre tg Gfi1b^fl/fl (Gfi1b^ko/ko; both CD45.2⁺) mice were transplanted with 200 000 CD45.1⁺ bone marrow cells into lethally irradiated CD45.1⁺ mice. (C) Percentage of CD45.2–positive cells (% CD45.2) in the blood after transplantation acquired at indicated time points (n = 4). (D) CD45 chimerism in the blood was determined 24 weeks after transplantation in recipient mice (n = 4) overall (All) and for the indicated lineages. Myeloid (Mac-1), B-lymphoid (B220), T-lymphoid (CD3). The difference is significant (P ≤ .05) for CD45 chimerism between wt and Gfi1b-deficient cells, when all leukocytes are taken into account (All). (E) CD45 chimerism was determined 24 weeks after transplantation in the blood, bone marrow, spleen, and thymus of recipient mice (n = 4). (F) Frequencies of HSCs were determined in mice 24 weeks after transplantation with wt CD45.1 cells and with either wt CD45.2 BM cells or with Gfi1b-deficient CD45.2⁺ bone marrow cells (n = 4). (G) The relative proportion of HSCs originating from CD45.2 wt or CD45.2 Gfi1b-deficient HSCs was determined and is shown after electronic gating on CD150⁺CD48⁻ cells depicted in F. (H) HSCs, bone marrow (BM), splenocytes (SP), thymocytes (thy) from mice transplanted with wt CD45.1 and Gfi1b-deficient CD45.2 bone marrow cells were genotyped and tested for the presence of the wt (CD45.1) and Gfi1b flox and Gfi1b ko alleles. (I) The frequencies of HSCs in mice either transplanted with wt CD45.1 and wt CD45.2 bone marrow cells or mice transplanted with wt CD45.1 and Gfi1b-deficient (MxCre tg Gfi1b^fl/fl) bone marrow cells was determined (n = 4, P ≤ .01). (J) Quantification of which proportion of HSCs originates from CD45.2 wt or CD45.2 Gfi1b-deficient HSCs in mice transplanted with wt CD45.1 and wt CD45.2 bone marrow cells or mice transplanted with wt CD45.1 and Gfi1b-deficient bone marrow cells (MxCre tg Gfi1b^fl/fl; n = 4, P ≤ .01). (K) The frequency of HSCs circulating in the peripheral blood of mice either transplanted with wt CD45.1 and wt CD45.2 bone marrow cells or mice transplanted with wt CD45.1 and CD45.2 Gfi1b-deficient bone marrow cells (MxCre tg Gfi1b ^fl/fl; n = 4, P ≤ .01). (L) Quantification of which proportion of HSCs circulating in blood originates from CD45.2 wt or CD 45.2 Gfi1b-deficient HSCs in CD45.1 mice transplanted with wt CD45.1 and wt CD45.2 bone marrow cells or CD45.1 mice transplanted with wt CD45.1 and Gfi1b-deficient bone marrow cells (n = 4, P ≤ .01). (M) Quantification of which proportion of Lin⁻, Sca-1⁺, c-kit⁺ (LSK) cells in bone marrow originate from CD45.2 wt or CD45.2 Gfi1b-deficient HSCs in CD45.1 mice transplanted with wt CD45.1 and wt CD45.2 HSCs or CD45.1 mice transplanted with wt CD45.1 and Gfi1b-deficient bone marrow cells (n = 4, P ≤ .01).