Cell-cycle status and apoptosis of Mll5−/− HSC. (A, left) Representative FACS data showing Pyronin-Y and DAPI staining of LSK cells from an Mll5−/− mouse and a control littermate. The gates used to discriminate cells in different stages of the cell cycle are shown. (Bottom left quadrant) G0; top left quadrant: G1; top right quadrant: S/G2/M. (Right panel) The graph summarizes cell-cycle data obtained from Mll5−/− and control mice (4 mice per group). (B, left) Representative FACS data showing BrdU incorporation in LSK and myeloid progenitor (Lin−, Sca-1−, c-kit+) cells from an Mll5−/− mouse and a control littermate following a single injection of BrdU (1 mg) 2 hours before analysis. (Right panel) The graph shows the relative frequencies of BrdU+ cells in LSK and myeloid progenitor populations from Mll5−/− and control mice (4 mice per group). (C, left) Representative FACS data showing annexin-V and DAPI staining of LSK cells in an Mll5−/− mouse and a control littermate. (Right) The graph shows the relative frequencies of apoptotic (annexin-V+ DAPI−) LSK cells in Mll5−/− and control littermate mice (7 mice per group).