Skp2 deficiency enhances the colony-forming ability and long-term reconstitution ability of BM. (A) The colony formation ability of BM cells from WT and Skp2^−/− mice (*P < .05; n = 3). (B) The long-term culture-initiating cell (LTC-IC) assay results showed that BM cells from Skp2^−/− mice had higher colony formation ability than those from WT mice (*P < .05, **P < .01, ***P < .001; n = 8). (C) Kaplan-Meier plot analysis of cumulative survival of the irradiated recipient mice injected with WT and Skp2^−/− BM cells after the fifth round of transplantation (log-rank value = 0.024; n = 5). (D) Analysis of LSK population in WT and Skp2^−/− recipient mice by flow cytometry after the first round of transplantation (*P < .05; n = 5). (E) G₀ and G₁ phases of LT-HSCs from WT and Skp2^−/− recipient mice were determined by flow cytometric analysis after the first round of BM transplantation. (*P < .05; n = 5). (F) The colony-forming ability of BM cells from the recipient mice after the first and second round of transplantation (*P < .05; n = 3).