Figure 3. c-kit⁺-enriched bone marrow cells acquired characteristics of odontoblasts. (A) Odontoblasts (Od) in the post-natal day 7 mouse first lower molar expressed Dsp/Dpp as shown by in situ hybridization. (B,C) Indirect immunofluorescence shows that they also secreted DSP (B) and DMP-1 (C) proteins. (D) In re-associations cultured for 20 days, EGFP-labeled cells derived from c-kit⁺-enriched bone marrow cells are detected in both epithelial and mesenchymal compartments. (E) Superimposition of Dsp/Dpp in situ hybridization with EGFP⁺ cells visualized in (D) shows that c-kit⁺-enriched bone marrow cells engrafted in the odontoblast layer expressed Dsp/Dpp. (F–I) In re-associations cultured for 20 days, the EGFP⁺ bone marrow cells engrafted in the odontoblast layer (G) developed cell processes (F and G, white arrows) and secreted DSP (H), which was deposited in the dental matrix (DM) between odontoblast processes (white arrows), as better visualized in the merged image (I). (J–M) These cells also secreted DMP-1 proteins. Am, Ameloblasts; CK-14, cytokeratin-14; DM, Dental Matrix; Mes, Dental Mesenchyme. Bar = 40 µm (A, D, E) and 10m (B, C, F–M).