Mouse adult hematopoietic stem cells actively synthesize ribosomal RNA

Low translation activity in HSCs. Mice were injected with 2 mg puromycin only for 10 min or with 20 µg harringtonine for 15 min, then 2 mg puromycin for 10 min, and noninjected mice were used as controls. (A) FACS profile of puromycin levels in whole BM cells of control mice (gray), mice injected with puromycin only (red), or harringtonine and puromycin (blue). (B) Quantification of puromycin levels in the indicated populations, relative to puromycin levels in the unsorted BM cells of mice injected with puromycin alone (HSC: Lin^– Sca1⁺ cKit⁺ CD34^–; MPP: Lin^– Sca1⁺ cKit⁺ CD34⁺; CMP: Lin^– Sca1⁺ cKit⁺ CD34^hi FCγRII/III^hi; GMP: Lin^– Sca1⁺ cKit⁺ CD34^low FCγRII/III^lo; MEP: Lin^– Sca1⁺ cKit⁺ CD34^low FCγRII/III^lo). For comparisons of puromycin levels between HSCs and other populations in mice injected with puromycin only, statistical significance was calculated using one-way ANOVA with Dunnett's correction for multiple comparisons: (†) P < 0.05, (†††) P < 0.001, and (††††) P < 0.0001. For comparisons of each population between mice injected with puromycin ± harringtonine, statistical significance was calculated using unpaired two-tailed Student's t-tests: (*) P < 0.05, (**) P < 0.01, (***) P < 0.001. n = 3 mice for each sample group; results representative of two independent experiments.