Figure 1.

eGFP ⁺ donor chimerism was achieved in the bone marrow but not in the brain of 25 mg/kg busulfan‐conditioned transplant recipients. (A) 2 × 10⁷ eGFP ⁺ bone marrow (BM) cells were delivered via the tail vein of C57BL/6J (WT) mice that received either 25, 50, 75 or 125 mg/kg busulfan. Untransplanted C57BL/6J and OK‐GFP ⁺ mice were included as controls (n = 8 mice/group). (B) Bone marrow and brain chimerism, as well as blood‐brain barrier (BBB) permeability by IgG staining, were determined 8 weeks post‐transplant. No changes in BBB permeability were observed. (C) Brain chimerism was established by counting eGFP ⁺ cells from six coronal sections per mouse using HistoQuant software (Bregma; 0.98, 0.26, −0.46, −1.18, −1.94 and −2.62 mm; 1 to 6; see Figure S2). Brain section 4 is shown with the boxed area enlarged to highlight eGFP ⁺ donor‐derived cells. ***P < 0.001. Error bars represent the SEM. Bar = 25 μm.