The morphogenesis of fungiform papillae occurs in a stereotyped pattern on the dorsal surface of the tongue in mice from embryonic day 12 (E12) to E17. The histological results and ultrastructural observations showed the development of specific structures in the epithelium into fungiform papillae. Prior to the morphological changes, the Bmp-4 and Shh transcripts are expressed in a restricted area on the dorsal surface. These results suggest that the development of fungiform papillae requires an epithelium and mesenchyme interaction during morphogenesis. In order to obtain direct evidence of the epithelium and mesenchyme interaction during tongue papillae morphogenesis, the formation of fungiform papillae was examined after a recombination assay. In order to confirm the epithelium and mesenchyme interactions during the early development of the mouse tongue, a recombination assay was conducted after the recombination assay at E12.5 and E13.5 for 2 days using an in vitro organ culture. From the recombination assay results, the E13.5 epithelial portion of the fungiform papillae could determine the position of the newly formed fungiform papillae with the epithelial signaling molecules. E13.5 was a critical stage for fungiform papillae morphogenesis. Fungiform papillae can be considered to be small epithelial appendages, which are formed via the epithelium and mesenchyme interactions.
Bibliographical noteFunding Information:
The authors wish to thank Dr. Shizuko Ichinose (Instrumental Analysis Research Center for Life Science, Tokyo Medical and Dental University) for her technical support, and Dr. Y.-P. Chen for providing the Bmp-4 and Shh plasmids. This work was supported by Korea Research Foundation Grant (KRF-2000-015-DP0363).
All Science Journal Classification (ASJC) codes
- Cell Biology