Suz12 is critical for maintaining adult HSC self-renewal and homeostasis. (A) Experimental design for competitive BM transplantation assays. (B) Analysis of test donor contribution (CD45.2⁺) to the peripheral blood of mice receiving either Suz12^fl/fl/CreER^T2 or Suz12^+/+/CreER^T2 BM cells with tamoxifen (TAM) or vehicle (ethanol [EtOH]) treatment. (C) Representative flow cytometric plots of hematopoietic stem and progenitor cell populations in BM of mice that received Suz12^fl/fl/CreER^T2 donor BM 16 weeks after tamoxifen (TAM) or vehicle (EtOH) treatment. The numbers represent the proportions of cells gated from the indicated populations. (D) Analysis of test donor contribution (CD45.2⁺) to the spleen (SPL), mesenteric lymph nodes (MLN), thymus (THY), BM, lineage⁻ Sca-1⁺ c-Kit⁺ (LSK) cells and BM lineage⁻ Sca-1⁻ c-Kit⁺ myeloid progenitors (MP) in mice receiving either Suz12^fl/fl/CreER^T2 or Suz12^+/+/CreER^T2 BM cells and tamoxifen (TAM) or vehicle (EtOH) treatment. Data represent mean ± standard deviation from Suz12^+/+/CreER^T2 (n = 3 donors) and Suz12^fl/fl/CreER^T2 (n = 4 donors) mice. Each data point represents the average test donor contribution from 3 recipients of BM from an individual donor. A two-tailed Student t test was performed to test statistical significance between vehicle (EtOH) and tamoxifen (TAM)-treated groups. BMT, bone marrow transplant; NS, nonsignificant; PB, peripheral blood. *P < .05; **P < .005; ***P < .001.