Wip1 deficiency specifically promotes myeloid progenitor cell development toward the granulocyte lineage. (A) Myeloid progenitor cell populations of 6-week-old mice were assayed by flow cytometry. Plots shown were the gated Lin⁻Sca1⁻c-kit⁺ cells. Right panel: Percentage of whole BMCs and absolute number of progenitors per BM sample isolated from femurs and tibiae (mean ± SD, n = 5 mice of each genotype). (B) The absolute number of MPPs and LT-HSC compartment in WT and Wip1KO mice was shown (mean ± SD, n = 4 mice of each genotype). The expression of CD48 and CD150 were analyzed with gating Lin⁻Sca1⁺c-kit⁺ (LSK) population. (C) Colony formation by 4 × 10⁴ BMCs from WT or Wip1KO mice in methylcellulose containing various concentrations of G-CSF (mean ± SD, n = 3) was detected. Colony counts were performed at day 10. (D) A total of 500 GMPs sorted out of individual WT and Wip1KO mice were seeded in methylcellulose media supplemented with SCF and G-CSF. The experiment was performed in triplicate. Differentiated cells were analyzed by FACS at day 8 of culture. Data are the mean ± SD The cell numbers positive for the surface marker CD11b⁺F4/80⁻Ly6G⁺ (neutrophils), or for CD11b⁺F4/80⁺Ly6G⁻ (monocytes/macrophages), and CD11b⁻Ly6G⁻F4/80⁻ (others; undifferentiated cells) were assayed. One representative CFU generated from WT or Wip1KO GMP after culture with G-CSF was photographed and is presented (E). Scale bars represent 100 μm. (F) The neutrophil cell number per CFU was calculated. (G) The neutrophil cell number per 500 GMPs was calculated. Data are representative of 3 independent experiments. Data presented are mean ± SD. *P < .05, compared with WT controls. **P < .01, compared with WT controls. ***P < .001, compared with WT controls.