Wif1 mice are less quiescent in BM, more prevalent in spleen, and depleted after 5-FU treatment. (A) Left panels: A representative cell cycle profile of flow-sorted LSK cells further stained with Hst/PY, gating on viable LSK cells. The table below the plots: Data from 4 separate experiments using sorted LSK cells from 3 to 5 mice for each strain as mean (SD) at 2.5 to 6 months of age. Right panels: An alternative cell cycle method using the Ki67 antibody as a marker for proliferation and DAPI for DNA content, gating on LSKCD48⁻ cells. The table below: Data from 5 individual mice of each strain. For both methods, the bottom left quad represents G₀; top left quad, G₁; and top right, S/G₂/M. Significance was determined by paired 2-tailed t test. (B) The top flow profiles display representative plots of the LSKCD48⁻ cells in the spleens of OB (left) and Wif1 (right) mice. Bottom bar graph: There are significantly more LSKCD48⁻ cells in the spleens of Wif1 mice (white bar) than control OB (black bar; P = .033), although this significance is lost in the LSKCD48⁻CD150⁺ population (P = .419). Significance was determined by paired 2-tailed t test; n = 5 mice/strain. (C) Wif1 mice die of repeated 5-FU administration. Control OB (▴) and Wif1 (□) mice were intraperitoneally injected with 100 mg/kg 5-FU once a week. Results are represented as the percentage of surviving mice over an 11-week time period, after which all Wif1 mice died (n = 10).