Early development of the zebrafish (Danio rerio) pharyngeal dentition (Teleostei, Cyprinidae).

In order to build a reference system to assess ongoing in vitro and in situ hybridisation experiments on epithelial-mesenchymal interactions governing odontogenesis in the zebrafish, we describe here the generation of the pharyngeal dentition, and the histological development of teeth up to fourteen days post-fertilization, using serial semithin sections, handmade and computer-assisted reconstructions and transmission electron microscopy. The tooth pattern in larval zebrafish is generated in a predictable, and bilaterally symmetrical manner from shortly before hatching onwards. Characteristics related to tooth development and structure differ considerably from those seen in juvenile specimens and those described for other bony fishes. Particular features related to the cyprinid condition include the complex epithelial connectivity and the mode of attachment of the teeth.