The transgene consists of 2.3 kb of genomic DNA containing the amelogenin promoter region and the untranslated first exon, approximately 1.3 kb of intron 1, and the coding sequence for amelogenin - including the signal peptide necessary for secretion of the protein into the extracellular enamel space - with a 27-amino acid sequence containing the FLAG epitope replacing amino acids 3-42. The amelogenin stop codon is followed by the luciferase gene with its polyadenylation signal. (J:100004)