The combined knockout of Kdm4a, Kdm4b, and Kdm4c leads to reduction of myeloid and lymphoid cells. (A) Schematic drawing of the experimental setup. Lethally irradiated mice were transplanted with BM from mice with the indicated genotypes (CD45.2) mixed 1:1 with BM from B6-SJL mice. (B) CD45.2 chimerism in PB at the indicated times after injection of tamoxifen (TAM). Data represented as mean ± standard deviation (SD) (n = 6 in each group). (C) Histogram depicting the CD45.2 percentage in the indicated cell populations within the BM 4 months after tamoxifen injection. Data represented as mean ± SD (n = 6 in each group). Hematopoietic stem cell (HSC; Lin⁻Sca⁻c-Kit⁺CD34⁻), LSK (Lin⁻Sca⁻c-Kit⁺), and granulocyte-monocyte (GM) progenitor (GMP) population. (D) Cell-cycle profile of LSK cells sorted from the BM of mice that were treated 10 days with tamoxifen and an additional 72 hours with 5-bromo-2′-deoxyuridine (BrdU). The percentage of BrdU⁺ cells in the different populations is indicated. Data are represented as mean ± SD (n = 4 in control group and n = 3 in the Kdm4abc knockout [KO] group). (E) In vitro growth curve of HSCs sorted from BM of mice with indicated genotypes 2 weeks after injection of tamoxifen. Data are represented as mean ± SD (n = 4 in each group). (F) Methocult replating assay using LSK cells sorted from the BM of mice with the indicated genotypes 2 weeks after injection of tamoxifen. One thousand cells per plate were plated in the first round and 5000 in the subsequent rounds of replating. Data are represented as mean ± SD (n = 3 in each group). Rel., relative.