Depletion of Ezh2 in hematopoietic cells in adult mice does not greatly compromise hematopoiesis. (A) Schema of conditional deletion of Ezh2 in adult mice. BM cells from 8-week-old Cre-ERT and Cre-ERT;Ezh2^fl/fl mice were transplanted into lethally irradiated recipient mice without competitor cells. At 8 weeks after transplantation, recipient mice were injected with tamoxifen for 5 consecutive days, and their PB was monitored for 32 weeks. (B) Donor chimerism and lineage contribution in PB. The chimerism of CD45.2⁺ donor-derived cells in PB of recipient mice was monitored for 32 weeks after injection of tamoxifen (left panel). Lineage contribution of donor cells to myeloid (Gr-1⁺ and/or Mac-1⁺), B (B220⁺), or T (CD4⁺ and or CD8⁺) cells is also shown in the right panel. Data are mean ± SD (n = 10). (C) PB cell counts of recipients repopulated with Cre-ERT and Cre-ERT;Ezh2^fl/fl BM cells after deletion of Ezh2 by tamoxifen injection. Data are mean ± SD (Tie2-Cre, n = 8; Tie2-Cre;Ezh2^fl/fl, n = 9). Statistical analysis was performed using 2-way repeated-measures ANOVA. (D-G) Absolute numbers of BM cells (D), KSL HSC/MPPs (E), Lin⁻ cells (F), and CMPs, GMPs, and MEPs (G) in BM of the recipient mice at 32 weeks after tamoxifen injection. Data are mean ± SD (n = 6). **P < .005.