ABSTRACT
Epithelial differentiation and morphogenesis in skin and oral mucosa were elucidated using various experimental tools. However, tongue epithelial differentiation has not been examined properly yet. In this study, we identified the relationship between morphological changes and localizations of differentiation markers, such as cytokeratins and PAX 9 in mice embryonic tongue development. Protective barrier formation and localization pattern of cytokeratins in tongue epithelium were examined with toluidine blue staining and immunohistochemistry respectively. Localization patterns of PAX 9 and Cytokeratin 14 were coincided during tongue epithelium development. In addition, compared with Ki67 localizations, marker for cell proliferation, localization patterns of PAX 9 and Cytokeratin 14 would suggest that these factors would involve in tongue barrier formation through cell proliferation. Based on these results, tongue epithelial differentiation would begin at E14 with the specific localizations of PAX 9 and Cytokeratin 14 prior to protective barrier formation then Cytokeratin 1, keratinization marker, would involve in protective barrier and filiform papillae formations.