Figure 4

Depletion of B and T lymphocyte precursors in the bone marrow and thymus in mice with the loss of MYSM1 DUB catalytic activity. Flow cytometry analyses were performed on Mysm1^+/+, Mysm1^−/−, and Mysm1^DN/DN mice, analyzing (A) the bone marrow for the following B cell populations: Fraction A (FrA, B220⁺IgM⁻IgD⁻CD43⁺CD24^loBP1^lo), Fraction B (FrB, B220⁺IgM⁻IgD⁻CD43⁺CD24⁺BP1^lo), Fraction C (FrC, B220⁺IgM⁻IgD⁻CD43⁺CD24⁺BP1⁺), large pre-B cells (B220⁺CD19⁺IgM⁻IgD⁻CD43⁻IL7Rα^hiFSChi), small pre-B cells (B220⁺CD19⁺IgM⁻IgD⁻CD43⁻IL7Rα^loFSC^lo), immature B cells (B220⁺IgM⁺IgD⁻), mature B cells (B220⁺IgM⁺IgD⁺); and (B) the thymus for double negative thymocytes DN1 (CD45⁺CD4⁻CD8⁻CD44⁺CD25⁻), DN2 (CD45⁺CD4⁻CD8⁻CD44⁺CD25⁺), DN3 (CD45⁺CD4⁻CD8⁻CD44⁻CD25⁺), and DN4 (CD45⁺CD4⁻CD8⁻CD44⁻CD25⁻), double positive thymocytes (DP, CD45⁺CD4⁺CD8⁺), and single positive thymocytes (CD45⁺CD4⁺CD8⁻ and CD45⁺CD4⁻CD8⁺). The data is from 3 to 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; bone marrow cell counts are presented per two tibias and femurs. (C) Representative flow cytometry plots of the mouse bone marrow stained for B220 and CD19 B cell markers and (D) of the mouse thymus stained for CD4 and CD8; the average frequencies of cells in the gates are presented as mean ± st. dev.