Gadd45a^−/−mice showed a normal hematologic phenotype under homeostatic condition. (A) Expression of Gadd45a mRNA in the indicated subpopulations of BM from young wild-type mice (2 months old) was measured by qRT-PCR (SYBR green assay). The relative expression of Gadd45a was normalized to glyceraldehyde-3-phosphate dehydrogenase (GAPDH) or β-actin. Each subpopulation was compared with LT-HSCs for statistical analysis (n = 4). (B-D) The absolute number of LT-HSCs (CD34⁻Flt3⁻Lin⁻c-Kit⁺Sca-1⁺), ST-HSCs (CD34⁺Flt3⁻Lin⁻c-Kit⁺Sca-1⁺), MPPs (CD34⁺Flt3⁺Lin⁻c-Kit⁺Sca-1⁺), LSK (Lin⁻c-Kit⁺Sca-1⁺) cells, HPCs (Lin⁻c-Kit⁺Sca-1⁻, LKS⁻), common myeloid progenitors (CD34⁺CD16/32⁻LKS⁻), GMPs (CD34⁺CD16/32⁺LKS⁻), and megakaryocyte/erythroid progenitors (CD34⁻CD16/32⁻LKS⁻) in young mice was determined by FACS (n = 11) (*P < .05, **P < .01, ***P < .001). N.S., not significant.