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Dental and Oropharyngeal Morphogenesis: Germ-layer Stability, Homology and Evolution.
Soukup, Vladimír ; Černý, Robert (advisor) ; Krylov, Vladimír (referee) ; Matalová, Eva (referee)
The vertebrate oropharyngeal cavity is a complex organ system housing food intake apparatus that is composed of hard- structured elements, the teeth. This apparatus is built upon mutual interactions between the epithelium and the underlying mesenchyme, which, however, take place only after the establishment of boundaries between the ectoderm and endoderm within this epithelium. Although possibly stereotypically positioned within the mandibular arch, our comparative morphogenetic survey identified that boundaries between ectoderm and endoderm are a result of different development in different vertebrate clades due to formative and constraining events taking place at early embryonic period. Dissimilar morphodynamics of ectoderm and endoderm are subsequently mirrored in the epithelial derivation of respective teeth in such a way that, e.g. in the Mexican axolotl, the oral teeth eventually display ectodermal, endodermal and ecto- endodermal derivation. Moreover, the ecto- endodermal boundary could have a tooth- inductive role, ...
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