Identification of Dlx3 protein at late bell stage of mammalian tooth development by immunohistochemistry

A defect in the DLX3 gene has been found to be responsible for the inherited disease known as Tricho-Dento-Osseous syndrome (TDO). Individuals affected present with hair, bone and teeth malformations including defects in enamel and root formation. In order to begin to understand the role of DLX3 in tooth development, experiments were designed to determine when and where is this protein expressed during tooth development using immunohistochemistry. Our results showed that during crown stage of tooth development, Dlx3 expression was seen in the odontoblasts, presecretory and secretory ameloblasts. During root formation stages, Dlx3 was seen in the forming Hertwig's epithelial root sheath (HERS). Dlx3 was also localized in the stellate reticulum and some cells of the apical root-mesenchyme. These results provide an insight into why defects in enamel and root formation are prevalent in TDO patients.