COMPARATIVE-ANALYSIS OF MOUSE DSP AND DPP EXPRESSION IN ODONTOBLASTS,PREAMELOBLASTS, AND EXPERIMENTALLY-INDUCED ODONTOBLAST-LIKE CELLS

Dentin sialoprotein (DSP) and dentin phosphoproteins (DPP) are uniquel y expressed by differentiating and fully differentiated mature odontob lasts. It is likely that DSP and DPP actively participate in the conve rsion of predentin to dentin. To compare the expression patterns of DP P and DSP, we constructed mouse cDNA probes. Northern analyses confirm ed their specific expressions in tooth germ-derived RNA and showed tha t the probes reacted with similar or identical multiple transcripts. I n situ hybridization indicated that DSP and DPP transcripts were uniqu ely detected and codistributed in developing mouse odontoblasts and pr eameloblasts. These data, as well as the adjacent positioning of the D SP and DPP coding sequences, suggest that common regulatory mechanisms control DSP and DPP expressions. Dental papillae cultures, in which o dontoblast differentiation was experimentally induced with TGF beta 1 combined with heparin, were used to show that the two molecules are al so coexpressed under in vitro conditions.