Deletion of miR-29a/b-1 is associated with increased HSPC cell cycling and apoptosis. (A-B) Cell cycle analysis by staining DNA content of fixed cells with DAPI. Fewer LSK cells, but not committed progenitor cells, accumulated in the G1/G0 stages of the cell cycle in miR-29a KO mice. (C-D) Increased numbers of annexin V⁺ LSK cells, but not myeloid progenitor cells, were present in both miR-29a KO and Het mice compared with WT. Details of annexin V staining and cell cycle staining for specific HSPC populations are summarized in supplemental Figures 5 and 7. Error bars indicate SEM. Each group has 7 to 10 mice from different experiments. Statistical significance was calculated using a Student t test: *P < .05; **P < 0.01.