Figure 4. Ddr2 expression in craniofacial skeleton.

(a) Whole-mount X-gal staining (green) of Ddr2^Lacz/+ skulls showing of Ddr2 expression in midfacial region, cranial vault, and cranial sutures. Scale bar: 50 μm. (b) X-gal staining of cryostat sections of calvaria from newborn mice showing expression in suture mesenchyme, periosteum, and dura mater of flanking bones. Scale bar: 100 μm, left and 50 μm, right. (c) X-gal staining of cryostat section of ISS (top) and SOS (bottom) from newborn mice revealing Ddr2 expression in resting and proliferative chondrocyte zones, but low or undetected in terminal hypertrophic chondrocytes. Boxed regions are shown in higher magnification, right. Scale bar: 50 μm.

Figure 4—figure supplement 1. Ddr2-LacZ localization in craniofacial skeleton.

(a) In Ddr2^+/LacZ embryos harvested at E13.5, intense X-gal staining can be seen in the maxilla (Mx), mandible (Mn), cartilage primordia of cranial base (Cb, black arrowhead), nasal septum and tooth buds. No staining was detected in the brain (Br) (top row, whole mount X-gal staining; middle and bottom row, X-gal staining on frozen embryos). (b) Whole mount and frozen sections of calvariae from 3-month-old mice show intense X-gal staining in cranial sutures, periosteum and lining of bone marrow inside cranial bones.