FIGURE 8.

Expression of BSP and Col1a1 in the interdental alveolar bones. Immunohistochemical staining was performed on tooth sections of 3-month-old WT mice (A), Dmp1 KO mice (B), and Dmp1 KO/DSPP Tg mice (C) with an anti-BSP antibody. Strong BSP signals (brown) were observed in the interdental alveolar bone between the first and second mandibular molars of WT (A) and Dmp1 KO/DSPP Tg mice (C), whereas Dmp1 KO mice (B) displayed markedly reduced signals. In situ hybridization was performed to assess the relative expression of Col1a1 from 1-month-old WT mice (D), Dmp1 KO mice (E), and Dmp1 KO/DSPP Tg (F) mice. The Col1a1 mRNA (signal in red) was restricted predominantly to the periodontal ligament. Its expression was reduced in Dmp1 KO mice (E) compared with WT mice (D). The transgenic expression DSPP (F) increased Col1a1 expression to a level similar to that in the WT mice. rd, radicular dentin; pl, periodontal ligament; ab, interdental alveolar bone. Scale bars = 100 μm (A, B, and C) and 50 μm (D, E, and F).