|Budget Amount *help
¥7,700,000 (Direct Cost : ¥7,700,000)
Fiscal Year 1997 : ¥1,800,000 (Direct Cost : ¥1,800,000)
Fiscal Year 1996 : ¥5,900,000 (Direct Cost : ¥5,900,000)
(1)Mouse amelogenin chromosomal DNA was cloned and investigated the structure. The exon-intron structure was analyzed by PCR technique, and the up-stream of 1st exon of the gene (about 3000 base pair) was sequenced. TATA box, inverted CCAAT, GATA-1, AP- 1, GR structure were identified in the region of gene expression controling regin.
(2)Bovine enamelin cDNA was cloned from bovine ameloblast cDNA libraiy using PCR product of porcine enamelin as probe. The cloned cDNA was inserted into pET29c (+) expression vector, and the recombinant bovine enamelin peptide was produced by E.coli. The peptide was immunized to rabbit, antibody against recombinant bovine enamelin was obtained. The antibody was used in the immunohistochemical analysis of bovine tooth germ. The production and secretion of the enamelin was seemed to relate with calcification of the enamel matrix.
(3)The proteinases involved in tooth resorption was investigated by comparing the active and resting phases of root-resorbing tissue. RNA was extracted from root-resorbing tissue of bovine mandible. Using RT-PCR and Northern blot analysis, the expression of proteinase mRNAs in both active- and resting-phase tissues was investigated. The results showed MMP-l, MMP-2, MMP-9, MMP-13, MTl-MMP, and cathepsin K mRNAs in both phases. Of these, MMP-1, MMP-9, and cathepsin K were expressed much more in the active root-resorbing tissue than in the resting tissue. Gelatin zymography showed that the root-resorbing tissue has gelatinolytic activity too. From these findings, it may be concluded that MMP-1, MMP-9, and cathepsin K play an important role in root resorption of deciduous teeth.