Fine structure of the oral epithelial cell surface in the Japanese lizard, Takydromus tachydromoides.

Abstract

Scanning electron microscopy was employed to investigate the ultrastructure of oral epithelialcells of the lizard, Takydromus tachydromoides. The specimens were prepared by a methodinvolving osmium postfixation and acid treatment to remove extracellular attached material.Bump-shaped protuberances were arranged symmetrically on both sides of the median line of thepalate. Epithelial surfaces besides the bump-shaped protuberances were widely covered with fine folds.At higher magnification, a network pattern of microridges was closely distributed over the entiresurface of the palate, and each cell marginal thickening was clear. The protuberances were alsoobserved in the latero-posterior region of the floor of the mouth. A number of nicks were arrangedsymmetrically on both sides along the median line of the fore-region of the floor. Taste buds werescattered in the epithelial surfaces between nicks. At higher magnification, microvilli as well as microridgeswere observed on the epithelial cell surfaces of the floor. There were no papillar structures onthe ventral tongue surface. Fine pits were densely distributed over the entire epithelial cellsurface. The cell margin was clearly distinguishable as a depressed line. The epithelial surface ofthe laryngeal part of the pharynx was entirely covered with ciliated cells. Taste buds were alsoscattered on the inner gingival epithelial surfaces of the upper and lower jaws along the dentalarches. Relatively indistinct microridges were widely distributed on the gingival epithelial cell surfaceof the upper jaw. Scrollwork and network patterns of microridges were clearly observed on the gin -gival epithelial surface of the lower jaw.