The epithelium of the tongue of Ambystoma mexicanum. Ultrastructural and histochemical aspects

The distribution pattern of taste buds and goblet cells and histochemical and ultrastructural aspects of the tongue epithelium of Ambystoma mexicanum are here described. This study is also concerned with the developmental stages and origins of the epithelial cells. Pavement cells and goblet cells of...

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Bibliographic Details
Published in:Annals of anatomy 1999-12, Vol.181 (6), p.523-536
Main Authors: Wistuba, J, Opolka, A, Clemen, G
Format: Article
Language:English
Subjects:
Ambystoma mexicanum - anatomy & histology
Ambystoma mexicanum - growth & development
Animals
Epithelial Cells - cytology
Epithelial Cells - ultrastructure
Larva
Mouth Mucosa - cytology
Mouth Mucosa - ultrastructure
Taste Buds - cytology
Taste Buds - ultrastructure
Tongue - cytology
Tongue - growth & development
Tongue - ultrastructure
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Summary:The distribution pattern of taste buds and goblet cells and histochemical and ultrastructural aspects of the tongue epithelium of Ambystoma mexicanum are here described. This study is also concerned with the developmental stages and origins of the epithelial cells. Pavement cells and goblet cells of the stratum superficiale are replaced by basal cells of the stratum germinativum in larvae and neotenous adults. The pavement cells of the larvae are characterized by a marginal layer of mucin grana. Decompaction of the mucins occurs immediately before extrusion in the adult. The larval goblet cell type (type I), which is also present in the adult, contains unfused grana of irregular shape. At the tip of the tongue, a further type (type II) of goblet cells is found. In the type II cells the intracellular secretory grana fuse to a single homogeneous mass. Leydig cells of the tongue epithelium are discerned by light microscopy first in the semi-adult, apparently correlated with partial metamorphosis. In the course of ontogenesis and induced metamorphosis the secretion changes to neutral glycoconjugates. The mucins of the pavement cells change first followed by those of the goblet cells. The glands of the secondary tongue show a dorso-ventral pattern of varying secretory qualities. Taste buds are found at the anterior margin of the tongue and along the base of the gill clasps in the early larva. They are already distributed all over the tongue at the end of the early larval phase.
ISSN:0940-9602
DOI:10.1016/S0940-9602(99)80057-0