Both alleles of PSF1 are required for acute reconstitution after BM ablation. (A) Time course of c-kit and Mac-1 expression in Lin⁻Sca-1⁺ cells during BM reconstitution after 5-FU injection (+/+, 8-week-old wild-type mice; +/−, 8-week-old PSF1^+/− mice). Results of FACS analysis are shown. Boxes indicate HSC-containing populations. Percentage of all BM cells corresponding to HSC population indicated by the box is shown in the right corner of each figure. (B) Total number of KSL cells derived from the femurs and tibias of wild-type (●) and PSF1^+/− mice (○) on the indicated days before (day 0) and after 5-FU injection as described in panel A. *P < .05 versus that in PSF1^+/− mice on the respective day.