Fig. 2

Assessment of bone marrow stromal cell chimerism. C57BL/6 mice received total body irradiation and were subjected to transplant with GFP-labelled bone marrow from C57BL/6-Tg14(act-EGFP)OsbY01 donor mice. Mesenchymal stromal cell lineage chimerism was determined by CFU-F assay, phenotypic analysis of bone marrow cells and histology after 8 weeks. a CFU-F assay results showing that the vast majority of CFU-F were GFP⁺ (donor-derived). Data are shown as individual data points from six mice for the transplanted group and three mice for the WT control group. b GFP positivity in the CD45^−/dimPdgfrα⁺Sca-1⁺ bone marrow MSC population. Shown are representative flow cytometry plots indicating gating strategy. Gating for GFP was based on a WT mouse sample. The percentage of CD45^−/dimPdgfrα⁺Sca-1⁺ cells positive for GFP (donor-derived) is shown as mean ± SD (n = 7). c Confocal microscopic images showing a GFP⁺ osteoclast (arrow) in the growth plate (GP) region (i), GFP⁺ perivascular cells (arrows) in bone (B) (ii) and bone marrow (iii), GFP⁺ bone lining cells (arrows) at the endosteal surface (iv) and a GFP⁺ osteocyte (arrow) embedded in bone matrix (v). Scale bars = 25 μm. CFU-F colony-forming unit fibroblasts, FSC forward scatter, Pdgfrα platelet-derived growth factor receptor α, Sca-1 stem cell antigen 1, SSC side scatter, WT wild-type, GFP green fluorescent protein, GP growth plate, B bone, MSC mesenchymal stromal/stem cell