[Enamelin transcriptional expression in developing postnatal rat tooth germ].

Objective: To observe the transcriptional expression of enamelin in developing postnatal rat first mandibular molar germs, for further studies of functions of enamelin in enamel development and mineralization.

Methods: Tissue slices of first mandibular molar germ of rat 1, 3, 7, 10, 14 days after birth were prepared. The enamelin mRNA expression was identified by in situ hybridization.

Results: Enamelin mRNA was observed in both ameloblast and odontoblast in 1-10 day old rat postnatal first mandibular molar germs. Enamelin mRNA appeared very weakly at 1st day, and increased through 3rd day, reached the maximum at 7th day, and reduced at 10th day and became negative at 14th day postnatally; while the expression of enamelin mRNA in odontoblast maintained lower from 1st to 10th day and negative at 14th day postnatally.

Conclusion: Enamelin gene transcriptional expression lasts from preameloblast to maturation ameloblast, which suggests that enamelin may participate in the development of enamel and mantle dentin.