CXCL12 mRNA expression during G-CSF–induced HPC mobilization. (A) WT mice were treated with G-CSF (100 μg/kg/d) for 5 days followed by a 2-day recovery period. The number of CFU-Cs in the blood (top panel) and CXCL12 protein expression in bone marrow extracellular fluid (middle panel) were measured at the indicated time points (n = 2, each). CXCL12 mRNA expression in the bone marrow was measured by directly flushing femurs with TRIzol and performing real-time RT-PCR on the recovered RNA. Shown is the relative amount of CXCL12 mRNA compared with β-actin mRNA (bottom panel). (B) Plot of CXCL12α protein versus CXCL12 mRNA (r2 = 0.56, P < .02). (C) WT and GEpoR mice (n = 6, each) were treated with G-CSF for 5 days and CXCL12 mRNA quantified. Data represent the mean ± SD. *P < .05 compared with day 0 or untreated mice.
