Figure 5

Hematopoietic dysfunction and altered hematopoietic progenitor cell numbers in Mysm1^DN/DN mice. Flow cytometry analyses were performed on the bone marrow of Mysm1^+/+, Mysm1^−/−, and Mysm1^DN/DN mice to quantify (A) common lymphoid progenitors (CLP, Lin⁻IL7Rα⁺cKit^loSca1^lo), common myeloid progenitors (CMP, Lin⁻cKit⁺Sca1⁻CD34⁺CD16/32⁻), granulocyte monocyte progenitors (GMP, Lin⁻cKit⁺Sca1⁻CD34⁺CD16/32⁺), megakaryocyte erythroid progenitors (MEP, Lin⁻cKit⁺Sca1⁻CD34⁻CD16/32⁻), and megakaryocyte progenitors (MkP, Lin⁻cKit⁺Sca1⁻CD150⁺CD41⁺); (B) hematopoietic stem cells (HSCs) and multipotent progenitors (MPP1-4), gated as LSK (Lin⁻cKit⁺Sca1⁺), followed by CD150⁺CD48⁻CD34⁻Flt3⁻ for HSCs, CD150⁺CD48⁻CD34⁺Flt3⁻ for MPP1, CD150⁺CD48⁺CD34⁺Flt3⁻ for MPP2, CD150⁻CD48⁺CD34⁺Flt3⁻ for MPP3, and CD150⁻CD48⁺CD34⁺Flt3⁺ for MPP4. The data is from 3–10 mice per genotype consolidated from two independent experiments. Bars represent means ± SEM; statistical analysis with ANOVA and Dunnett’s post-hoc test, comparing each group to the control, *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001, NS—not significant; bone marrow cell counts are presented per two tibias and femurs. (C) Representative flow cytometry density plots of the bone marrow of Mysm1^+/+, Mysm1^−/−, and Mysm1^DN/DN mice, gated on live Lin- cells and showing the LSK cell population (top), or gated on the LSK C150⁻CD48⁺ cells and showing the Flt3^lo MPP3 and Flt3^hi MPP4 cells; the average frequency of cells in the gates is presented as mean ± st. dev. While the LSK cell numbers are highly variable (top), a strong depletion of the lymphoid-primed MPP4 cells is consistently observed in all the Mysm1^−/− and Mysm1^DN/DN mice (bottom). (D) Colony forming units (CFU) assays showing depletion of pre-B and erythroid BFU-E progenitors in Mysm1^DN/DN and Mysm1^−/− mouse bone marrow; MMNC – marrow mononuclear cells.