From conical to spatulate: intra- and interspecific changes in tooth shape in closely related cichlids (Teleostei; Cichlidae: Eretmodini)
| Autor: | Kristel Wautier, Ann Huysseune, Erik Verheyen, Els Vandervennet |
|---|---|
| Rok vydání: | 2006 |
| Předmět: |
Eretmodus
Teleostei biology Ontogeny Enamel organ Adaptation Biological Enamel Organ Conical surface Anatomy Cichlids biology.organism_classification Biological Evolution stomatognathic diseases stomatognathic system Conical tooth Ameloblasts Animals Odontogenesis Animal Science and Zoology Eretmodini Tooth Tooth Germs Developmental Biology |
| Zdroj: | Journal of morphology. 267(4) |
| ISSN: | 0362-2525 |
| Popis: | The Eretmodini are closely related cichlids endemic to Lake Tanganyika with very divergent oral tooth shapes, ranging from spatulate in Eretmodus to conical in Tanganicodus. To study how closely related cichlids can generate such divergent tooth shapes, we investigated how the enamel organ directs the develop- ment of spatulate teeth in Eretmodus cf. cyanostictus (lin- eage A), both in ontogeny and in adults, and of conical teeth in adult Tanganicodus cf. irsacae, using 3D- reconstructions from serially sectioned tooth germs. The spatulate oral tooth shape that characterizes adult E. cf. cyanostictus (lineage A) is preceded early in ontogeny by a conical tooth shape. We propose two possible hypotheses to account for changes in the folding of the enamel organ (in particular its epithelio-mesenchymal boundary) capa- ble of generating such distinct tooth shapes. Different arguments lead us to favor the hypothesis of an asymmet- ric growth and differentiation of the enamel organ, such that the tip of a conical tooth corresponds to one "corner" of a spatulate tooth. Applying current molecular models of tooth shape variation, this would imply the existence of asymmetric fields of inhibition. Whether such asymmetric growth reflects the reutilization of a simple mechanism operating in ontogeny has to be clarified. J. Morphol. 267: 516 -525, 2006. © 2006 Wiley-Liss, Inc. |
| Databáze: | OpenAIRE |
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