Ultrastructure of secretory ameloblasts in puppies.

Four about 4-week-old puppies were fixed by perfusion; the secretory ameloblasts of the first molar tooth germs were observed with an electron microscope. The morphology of the puppy secretory ameloblast closely resembles that of man. In addition, the primary cilia and a pair of basal bodies were observed close to Golgi apparatus of the secretory ameloblast. Cytoplasmic microtubules radiated from the basal bodies. It is suggested that a pair of basal bodies may be the microtubule-organizing center of the secretory ameloblast. Further, melanocytes were present in the intermediate cell layer and aggregated melanosomes were present in the cytoplasm of both stratum intermedium cells and secretory ameloblasts.