Deletion of Rac in osteoblasts does not affect hematopoiesis. (A) Peripheral blood counts were similar between Racdel and Osx-Racdel mice for white blood cell count (WCC, 9.6 ± 2.2 × 103/μL vs 10.3 ± 3.4 × 103/μL, respectively, P = ns), hematocrit (HCT, 48.8% ± 3% vs 50.6% ± 0.8% respectively, P = ns) and platelet counts (973 ± 140 × 103/μL vs 1052 ± 164 × 103/μL, respectively, P = ns; n = 3-6 biologic replicates). (B) No difference in BM cellularity from Racdel and Osx-Racdel mice (9.6 ± 2.2 × 103/μL vs 10.3 ± 3.4 × 103/μL per 1 femur, respectively, P = ns), liver weight (1.3 ± 0.2 g vs 1.0 ± 0.1 g, respectively, P = ns), or spleen weight (0.06 ± 0.02 g vs 0.05 ± 0.01 g, respectively, P = ns; n = 3-6 biologic replicates). (C) Peripheral blood immunophenotype was similar between Racdel and Osx-Racdel for myeloid (10.8% ± 4.7% vs 13.5% ± 3.6%, respectively, P = ns), B cells (33.9% ± 17.8% vs 43.2 ± 5.6%, respectively, P = ns), and T cells (28.1% ± 28.1% vs 32.5% ± 7.3%, respectively, P = ns; n = 3-6 biologic replicates). (D) HSC and progenitor cell populations were similar between Racdel and Osx-Racdel mice; LKS+ 2248 ± 456 vs 2730 ± 303; multipotent progenitors (MPP), 1280 ± 323 vs 1580 ± 244; short-term HSCs (ST-HSC), 736 ± 127 vs 906 ± 131; and long-term HSCs (LT-HSC), 193 ± 29 vs 206 ± 52; P = ns for all, expressed per 1 × 106 BM cells, each dot represents individual biologic replicate. (E) Representative flow cytometry data plot demonstrating gating strategy for LKS+, MPP, ST-HSC, and LT-HSC. All values are means ± SD. Open boxes, Racdel; shaded boxes, Osx-Racdel.