CHD8 deletion causes increased HSPC apoptosis. (A) Immunophenotypic of SLAM HSC apoptosis by annexin V and 7-AAD staining at 6 days after deletion. Averaged frequencies of cells are shown. WT indicates Chd8^F/F mice. (B) Graph showing the percentage of annexin V⁺ and apoptotic (annexin V⁺ 7-AAD⁻) cells in SLAM HSCs. *P < .05; ***P < .001. (C) Ratio of annexin V⁺ cells in the LK population. ***P < .001. (D) Western blot of cleaved caspase 3 in sorted LK cells. The quantification represents data from 3 repeat experiments. (E) Cell cycle analysis by flow cytometry of Ki67 and 4′,6-diamidino-2-phenylindole in sorted LSK cells. Averaged frequencies of subpopulations are shown. (F) Percentage of LSK cells in G₀, G₁, and S-G₂-M phase in WT and Chd8^−/− mice. ***P < .001, **P < .01. (G) Cell cycle analysis by flow cytometry of Ki67 and 7-AAD in sorted SLAM-HSCs. Averaged frequencies of subpopulations are shown. (H) Percentages of SLAM HSC cells in G₀, G₁, and S-G₂-M phase in WT and Chd8^−/− mice are shown. **P < .01; *P < .05.