The objective of this study is to investigate the regulation controlling the expression of DMP-1 during odontogenesis. The regulational investigation of DMP-1 will be carried out on immortalized odontoblasts and ameloblasts. The potential function of the DMP-1 protein will be tested using transgenic mice over expressing DMP-1. Our Hypothesis is that the tissue and developmental expression of DMP-1 is regulated through discrete interactions of transcription factors with their cognate cis-elements and that DMP-1 has an important function in normal tooth mineralization. In order to test this hypothesis, the following specific aims will be met. 1. Determine the conserved cis-elements present in the DMP-1 promoter that potentially regulate this gene's expression pattern. 2. Determine the region of the DMP-1 promoter that confers the tissue- specific expression of DMP-1 gene during odontogenesis in vitro using immortalized cell lines and transgenic mice.