Transcriptional expression of Puma in HSCs and HPCs. (A) Basal expression of Puma mRNA in different hematopoietic cell subsets under homeostatic conditions. The different subsets of hematopoietic cells were sorted for real-time RT-PCR analysis to quantify the levels of gene expression. LT-HSC (CD34⁻LKS); ST-HSC (CD34⁺LKS); CMP, common myeloid progenitor (CD34⁺FcγR^lowCD127⁻LKS⁻); MEP, megakaryocyte/erythroid progenitors (CD34⁻FcγR^lowCD127⁻LKS⁻); CLP, common lymphoid progenitor (CD127⁺L⁻K^lowS^low); GMP, granulocyte-macrophage progenitor (CD34⁺FcγR^hiCD127⁻LKS⁻). The values on y-axis indicate the fold change normalized to β-actin. (B) Induced expression of Puma mRNA in LT-HSCs after irradiation. Each bar shows the mean ± SD from 3 replicates. *P < .05.