The effect of transgenic DPP on the collagen expression and organization in the Dspp-null mice.

In situ hybridization analyses of Col Ia1 mRNA in the mandibular first molars of 3-week-old mice indicated that there was no apparent difference in the signal intensities (pink/red color) in the odontoblasts among the three groups (A). Picro-sirius Red-staining showed that a great amount of larger-diameter collagen fibers were found in the predentin and dentin, and were disorganized in the Dspp-/- mice, whereas only a small amount of larger-diameter collagen fibers were restricted to the predentin in the Dspp+/- mice and Dspp-/-;DPP Tg mice. d, dentin; rp, radiocular pulp; pd, predentin; and od, odontoblast. Scale bars = 20 μm.