Meis1 regulates cell cycle of the HSC compartment.

<p>(A) Representative flow cytometric profiles showing Annexin V and 7-AAD staining of LSK cells from <i>Mx1-Cre⁺ Meis1</i>^fl/fl and control mice one week after poly(I:C) treatment. Bar graphs on the right represent the percentages of apoptotic LSK cells (anexin V⁺ 7-AAD⁻) cells from poly(I:C)–treated <i>Mx1-Cre</i>⁺<i>Meis1</i>^fl/fl (solid bars) and control <i>Meis1</i>^fl/fl (open bars) mice (mean and SD; n = 3). (B) Representative flow cytometric profiles showing BrdU incorporation and 7-AAD staining of LSK cells from <i>Mx1-Cre Meis1</i>^fl/fl and control mice one week after poly(I:C) treatment. Bar graphs shown on the right represent the percentages of cells in G0/G1-, S- and G2/M-phase of the cell cycle in the LSK cell population from poly(I:C)–treated <i>Mx1-Cre</i>⁺<i>Meis1</i>^fl/fl (solid bars) and control <i>Meis1</i>^fl/fl (open bars) mice (mean and SD; n = 3). **p<0.01.