Loss of Mll5 enhances cell-cycle transition of hematopoietic progenitor cells and affects the repopulation ability of normal and NUP98-HOXA10hd– expanded bone marrow cells. (A) Hematopoietic reconstitution in peripheral blood of wild-type mice transplanted with retrovirally marked bone marrow cells from Mll5^+/+ (n = 9) or Mll5^−/− (n = 10) mice. Chart depicts mean and SD of percent donor-derived cells (YFP-positive by FACS) in peripheral blood at 4, 8, and 12 weeks after transplantation (left panel). Hematopoietic reconstitution in peripheral blood of secondary transplants (right panel). (B) Hematopoietic reconstitution in peripheral blood of wild-type mice transplanted with bone marrow cells from Mll5^+/+ (n = 5) or Mll5^−/− (n = 6) mice transduced with NUP98-HOXA10hd. Chart shows percent donor-derived NUP98-HOXA10hd–expressing cells (GFP-positive by FACS) in peripheral blood at 4, 8, 12, and 18 weeks after transplantation (left panel). Hematopoietic reconstitution in peripheral blood of secondary transplants (right panel). (C) Gating strategy for lineage-negative and LSK cells and representative blots of cell-cycle distribution. (D) Cell-cycle distribution in lineage-negative (left panel) and LSK (right panel) bone marrow cells (BrdU injections intraperitoneally at 36, 24, and 12 hours before harvest) from 8-week-old Mll5^+/+ (n = 13) and Mll5^−/− (n = 15) mice. Cell-cycle phases were determined by analysis of 5-bromo-2-deoxyuridine (BrdU)/7-amino-actinomycin D (7AAD) staining by FACS, and the mean and SD of each phase is shown.