HSCs accumulate 60 and 96 hours but not 24 hours after pIpC-mediated NF-Ya deletion in the G₂/M phase of the cell cycle and present with increased apoptosis. (A left) A representative Ki67 versus DAPI staining of control and ko LSK/SLAM HSCs is shown 60 hours after pIpC treatment. (Right) Quantitative evaluation of the cell cycle analysis is based on DAPI and Ki67 stainings of viable LSK/SLAM HSCs 24, 60, and 96 hours after pIpC treatment (control [gray], n = 5; ko [black], n = 4; *P < .05; G₀ 24 hours, P = .09; G₀ 60 hours, P = .06; G₀ 96 hours, P = .06). (B left) A representative FACS plot of LSK/SLAM HSCs stained for annexin V and 7AAD is shown for control and ko. (Right) This bar graph shows the percentage of apoptotic (annexin V positive, 7AAD negative) and dead HSCs (annexin V, 7AAD double positive) for control (gray) and ko (black) samples 96 hours after pIpC treatment (n = 4); *P < .05.