Mysm1 deficiency results in a reduction of HSC and its progenitors. Absolute number of (A) BM cells and (B) LSK cells per femur (hind leg) of 8∼12-week-old WT and Mysm1^−/− mice; n = 9 mice per group. (C) Distribution of LSK cells and various LSK subsets in the WT and Mysm1^−/− BM: Lin negative-gated cells were assessed on the basis of their expression of Sca-1 and c-Kit (top); LSK-gated cells were further defined on the basis of the expression of CD34 and Flt3 (bottom). Numbers adjacent to outlined areas indicate frequency. (D) Absolute number of LSK subsets per femur in the WT and Mysm1^−/− mice on the basis of the gates in panel C; n = 8-10 mice per group. (E) Distribution of cells in LSK subsets in the WT and Mysm1^−/− mice, assessed by the expression of CD150 and CD48. (F) Absolute number of LSK subsets per femur in the WT and Mysm1^−/− mice on the basis of the gates in panel E; n = 8-10 mice per group. (G) Expression of Flt3 and CD34 in the WT and Mysm1^−/− BM LSK subsets gated as in panel E. (H) Absolute number of LSK subsets per femur in WT and Mysm1^−/− mice (n = 8-10 per group), stained as in panel G. (C,E,G) Data are representative of 3 independent experiments. *P < .05; **P < .01; ***P < .001.