Figure 1.

Ddr2^slie/slie mice failed to heal a calvarial subcritical size defect (SSD). Defects were generated as described in Materials and Methods. (A) Hematoxylin and eosin staining 3 d and 1 wk postsurgery of SSD for wild-type (WT) and Ddr2^slie/slie mice showing that defects are initially the same size in WT and mutant mice. (B) Representative micro–computed tomography (µCT) and histological images of the defect area showing amount of bone regeneration. Note that for panels A and B, low-power (left) and high-power images (right) are shown for each histological sample. (C) Measurements are shown for regenerated bone volume/total volume calculated as described in the Materials and Methods. Statistical analysis between WT andDdr2^slie/slie mice at each time point. n = 6–8 mice/group. *P < 0.05. **P < 0.001. Scale bars: histological sections = 50 µm, 2-dimensional µCT image = 500 µm, 3-dimensional µCT image = 2 mm.