Localization of microfilaments and microtubules during dental development in the rat.

Using monoclonal antibodies, changes in the localization of actin and tubulin in advanced dental development were studied. Structures were determined on paraffin sections by means of an indirect immunoperoxidase method. The distribution pattern of actin and tubulin was nearly identical. Immuno staining could be observed at the apical pole of the ameloblasts, the Tomes' fibres and the matrix of enamelum. The dental papilla showed an intense coronal reaction at the initial stage of formation of the dental papilla. With the onset of tooth development the distribution of actin and tubulin was concentrated on the apical pole of odontoblasts and ameloblasts. These results indicate the functional participation of actin and tubulin during secretory activity both in the dental papilla and the enamelum matrix. Perhaps, the intensely reacting apical process of the ameloblasts has a key role in the coordination of some of these processes.