Gene expression of BMP family and receptors during tooth development

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Bone morphogenetic proteins are diffusible signaling molecules regulating inductive tissue interactions and play inportant roles in epithelialmesenchymal interaction of organ structure during developmental stage. We examined BMPs gene expression during developmental stage of tooth germ using in situ hybridization method. All specimens were derived from C57BL mouse. All specimens were immersed in 4 % paraformaldehyde solution in phosphate buffer for 16 hr at 4℃. All fixed specimens were dehydrated in graded ethanol, processed in chloroform, and embedded in paraffin. Sections of 4mm were cutt and transferred to 3-(Triethcxysilyl)-propylamin coated slides and heated at 37℃ for 5 hr. BMP-2.3.4.5.6.7 specific digoxgenin-labeled single stranded RNA probes were prepared using an SP6/T7 transcription kit.BMP-4 and 7 gene expressions were observed from prenatal 11 days. BMP-2 gene expression was observed from paranatal 12 days. These protein expressions using immunohistochemistry were observed … More coincidence with gene expression. These results suggested BMP-2,4,7 were related with morphogenesis and tooth germ cell differentiation in epithelial mesenchymal interacton from early stage of tooth development. BMP-5 gene expression was observed inner enamel epithelium in the late cap stage. These results suggested BMP-5 play important role of enamel and dentin formation.The basement membrane (BM) assembly is a thin sheet-like highly specialized structure of extracellular matrix that separates the epithelial cells from the stroma. Type IV collagen, the major component of mammalian BM, is a family of six distinct polypeptide chains. These are designated alpha1(IV) to alpha6(IV)) and they are encoded by six distinct genes, COL4A1 to COL4A6. Odontogenesis is a complex process involving inductive and reciprocally inductive influences of odontogenic epithelium and ectomesenchyme, and the BM interposed between these two tissues functions as a regulator and modulator of these interactions. Previous studies have examined various BM constituents including collagen IV and laminin to determine their roles during tooth morphogenesis and cytodifferentation. In this study on mouse molar germ development, we observed that collagen IV isoforms localized in the dental BM at various stages of tooth organogenesis showed a stage- and position-specific distribution pattern. These results suggest that stage- and position-specific distribution of collagen IV isoform and BMPs related with tooth morphogenesis. Less