Résumé
BACKGROUND:Fungiform and circumvallate papillas on the surface of the mammal tongue mucosa are mainly associated with taste.Taste abnormalities seriously affect patients' quality of life,so it is of significance to understand the developmental processes of fungiform papilla and taste buds,for hypogeusia treatment.OBJECTIVE:To observe the morphological changes of mouse tongue fungiform papilla and taste buds during their developmental processes.METHODS:The tongues of C57BL/6J mice were observed by scanning electron microscope and hematoxylin eosin staining at embryonic days 13.5-18.5 (E13.5-E 18.5),postnatal (PN) days 0.5,4.5,7.5,14.5,21.5,90.5,and postnatal 1.5 years (PN1.5Y),and Shh antibody was used for immunohistochemical staining.Immunohistochemical staining of S-100 was performed on the tongue specimens of the mice at E16.5 and E18.5.RESULTS AND CONCLUSION:The number of fungiform papilla was mainly determined at E13.5-E14.5.From E15.5,the papilla gradually matured in morphology.Taste bud development began at E16.5,and the taste pore began to form at PN7.5.In adult and old age,taste bud cells and intercellular substances were reduced,and keratosis surrounding the fungiform papillae was visible.Shh was expressed in the epithelial cells of fungiform papilla at E14.5,in the epithelial cells at the tip of the fungiform papilla at E16.5 and E18.5,and in adult and elderly taste bud cells.These results suggest that Shh plays an important role in the development,maturation and maintenance of fungiform papillae and taste buds.S-100 is expressed in the connective tissue beneath the fungiform papillae at E18.5,indicating that the nerve extension may be involved in the development and maturation of taste buds.