Figure 2. Gsk3 knockdown increases cycling of the HSC-enriched LSK cell population.

(A) To assess cell cycle status of the HSC-enriched LSK population, sorted GFP⁺ LSK and GFP⁺ LSK Flk2^– cells from primary recipients of control and Gsk3-rnai 4 months after BM transplantation were stained with Hoechst and Pyronin and analyzed by FCM. Representative FACS data are shown for control versus Gsk3-rnai-C2. (B) At 4 months after BM transplantation, primary recipients of control and Gsk3-rnai were fed BrdU in the drinking water for 7 days. Sorted GFP⁺ LSK Flk2⁺ and Flk2^– cells were stained with BrdU-APC antibody and PI to analyze BrdU incorporation. Representative FACS data are shown for control versus Gsk3-rnai-C2. Similar results were obtained by BrdU versus 7-AAD staining (BD). Percent cells are shown for the indicated gates and quadrants. In A and B, lower left gate represents G₀, upper left represents G₁, and upper right represents S, G₂, and M phases of the cell cycle, as shown in the diagram in A.