Inducible deletion of Shp2 in vivo leads to decreased cellularity in peripheral blood, BM, and spleen. (A) Deletion of the floxed region was verified by PCR analysis of peripheral blood cells isolated from mice 2 weeks after final Poly-I:C injection. (B) Deletion of Shp2 in BM was verified by immunoblotting at 2 weeks after final Poly-I:C injection. Erk was used as loading control. (C) Complete blood cell counting. Peripheral blood was collected at time points after final Poly-I:C injection (n = 5-9). HCT indicates hematocrit; PLT, platelet; RBC, red blood cells; WBC, white blood cells. (D) Representative H&E staining of trabecular femur 2 weeks after final Poly-I:C injection indicates a severe hypocellular phenotype in fl/fl:cre⁺ BM. Top panels show images scanned by ScanScope Digital Slide Scanners with 100× magnification. Bottom panels scanned with 400× magnification. (E) BM cellularity decreased significantly in fl/fl:cre⁺ mice starting from 1 week after final Poly-I:C injection (n = 3-15). (F) Splenic cellularity in the mutant animal was significantly reduced. Time points were after final Poly-I:C injection (n = 3-4). ***P < .001, **P < .01,*P < .05, error bars are SD; see also supplemental Figure 1.