asrij KO HSPCs have reduced p53 protein levels and increased DNA damage. Floxed and KO cells from 2-month-old mice were compared in all cases (unless mentioned otherwise) and are indicated in red and light green, respectively. (A) RT-qPCR analysis for p53 transcript levels and (B) immunoblot analysis for p53 protein levels in HSPCs. (C) RT-qPCR analysis for p21, puma, noxa, bcl2, gga1, gfi1, and necdin transcript levels in HSPCs. (D-G) Representative Annexin V/7-AAD flow cytometry plots and graphs showing significantly reduced percentages of early and late apoptotic cells in 6-month-old KO HSPCs compared with floxed controls, both in vivo and ex vivo after short-term culture. (H) Immunoblot analysis for ϒH2AX protein levels to assess DNA damage in HSPCs. Histone H3 and GAPDH: loading controls. (A-H) n = 3 mice per genotype for each experiment. Statistically significant differences in transcript and protein levels were determined using ANOVA: single factor analysis. Error bars denote standard error of mean. *P < .05 and **P < .01. GAPDH, glyceraldehyde-3-phosphate dehydrogenase; RT-qPCR, reverse transcription quantitative polymerase chain reaction.