Wip1-deficient neutrophils showed normal cell death but increased cell proliferation. (A) Representative FACS analysis of blood and BM neutrophils for staining of anti–annexin-V and propidium iodide was shown. (B) Identical cell death kinetics of BM-derived neutrophils isolated from WT or Wip1KO mice was observed when cells were cultured in DMEM for different periods (mean ± SD, n = 3 for each genotype). Data are representative of 3 independent experiments. (C) BrdU incorporation in blood and BM-derived neutrophils was detected by FACS 96 hours after injection of BrdU. Increased percentage (D) and cell number (E-F) of BrdU⁺ neutrophils in the blood and BM of Wip1KO mice were detected 96 hours after BrdU injection. Data are representative of 5 independent experiments. Generated mixed chimeric mice by transplanting either CD45.1⁺ WT or CD45.2⁺ Wip1KO BMCs at the ratio of 1:1 into lethally irradiated CD45.1⁺ mice. By 6-8 weeks after BMT, BrdU were injected and BrdU⁺ neutrophils were detected (G-H). (G) Represent FACS of BrdU⁺ neutrophils derived from WT and Wip1KO BMCs in mixed chimeras are shown. (H) The mean neutrophil compartment percentages are analyzed 96 hours after BrdU injection (mean ± SD, n = 3 or 4). Data are representative of 3 independent experiments. ***P < .001 (WT vs Wip1KO).