A transgenic cassette carrying a genomic fragment comprised of the 9.6 kb 5'-flanking region, exon 1, intron 1, and a part of exon 2 of the mouse DMP1 gene fused to human HB-EGF (DT-R) cDNA with a polyadenylation signal was used to generate transgenic mice. Lines 2 and 4 were generated. This promoter conferred preferential expression of DT-R in osteocytes, but not in osteoblasts. (J:129907)