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A curriculum vitae of teeth: evolution, generation, regeneration.

Koussoulakou DS, Margaritis LH, Koussoulakos SL - Int. J. Biol. Sci. (2009)

Bottom Line: Over the course of 500,000,000 years of evolution, many of those structures migrated into the mouth cavity.In addition, the total number of teeth per dentition generally decreased and teeth morphological complexity increased.These interactions involve spatially restricted expression of several, teeth-related genes and the secretion of various transcription and signaling factors.

View Article: PubMed Central - PubMed

Affiliation: University of Athens, Faculty of Biology, Department of Cell Biology and Biophysics, Athens, Greece.

ABSTRACT
The ancestor of recent vertebrate teeth was a tooth-like structure on the outer body surface of jawless fishes. Over the course of 500,000,000 years of evolution, many of those structures migrated into the mouth cavity. In addition, the total number of teeth per dentition generally decreased and teeth morphological complexity increased. Teeth form mainly on the jaws within the mouth cavity through mutual, delicate interactions between dental epithelium and oral ectomesenchyme. These interactions involve spatially restricted expression of several, teeth-related genes and the secretion of various transcription and signaling factors. Congenital disturbances in tooth formation, acquired dental diseases and odontogenic tumors affect millions of people and rank human oral pathology as the second most frequent clinical problem. On the basis of substantial experimental evidence and advances in bioengineering, many scientists strongly believe that a deep knowledge of the evolutionary relationships and the cellular and molecular mechanisms regulating the morphogenesis of a given tooth in its natural position, in vivo, will be useful in the near future to prevent and treat teeth pathologies and malformations and for in vitro and in vivo teeth tissue regeneration.

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Diagram showing stages of teeth development, a few genetic factors affecting phenotypes, and some signalling molecules and growth factors expressed in the epithelial and mesenchymal components of developing teeth. [While most teeth-related genes exhibit, in general, similar expression patterns in the developing teeth in both humans and mice, several genes, including MSX1, FGF8, PAX9, and SHOX2, show some slightly different expression profiles]. [Arrows = activation; (T) = inhibition at the indicated stages; italic fond = genes; regular, bold fond = growth factors].
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Figure 5: Diagram showing stages of teeth development, a few genetic factors affecting phenotypes, and some signalling molecules and growth factors expressed in the epithelial and mesenchymal components of developing teeth. [While most teeth-related genes exhibit, in general, similar expression patterns in the developing teeth in both humans and mice, several genes, including MSX1, FGF8, PAX9, and SHOX2, show some slightly different expression profiles]. [Arrows = activation; (T) = inhibition at the indicated stages; italic fond = genes; regular, bold fond = growth factors].

Mentions: In conclusion, most of the signaling molecules that regulate epithelial-ectomesenchymal interactions during tooth development are members of the TGF (transforming growth factors), FGF, BMP, Hedgehog, EDA, Notch and WNT families. The ectomesenchymal expression of MSX1 and PAX9 remains strong from the initiation stage through the bell stage. The closely overlapping expression patterns of PAX9 and Msx1 genes are consistent with a role in epithelial-mesenchymal interactions. Their activity is down regulated at ED16 (Fig. 5).


A curriculum vitae of teeth: evolution, generation, regeneration.

Koussoulakou DS, Margaritis LH, Koussoulakos SL - Int. J. Biol. Sci. (2009)

Diagram showing stages of teeth development, a few genetic factors affecting phenotypes, and some signalling molecules and growth factors expressed in the epithelial and mesenchymal components of developing teeth. [While most teeth-related genes exhibit, in general, similar expression patterns in the developing teeth in both humans and mice, several genes, including MSX1, FGF8, PAX9, and SHOX2, show some slightly different expression profiles]. [Arrows = activation; (T) = inhibition at the indicated stages; italic fond = genes; regular, bold fond = growth factors].
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2651620&req=5

Figure 5: Diagram showing stages of teeth development, a few genetic factors affecting phenotypes, and some signalling molecules and growth factors expressed in the epithelial and mesenchymal components of developing teeth. [While most teeth-related genes exhibit, in general, similar expression patterns in the developing teeth in both humans and mice, several genes, including MSX1, FGF8, PAX9, and SHOX2, show some slightly different expression profiles]. [Arrows = activation; (T) = inhibition at the indicated stages; italic fond = genes; regular, bold fond = growth factors].
Mentions: In conclusion, most of the signaling molecules that regulate epithelial-ectomesenchymal interactions during tooth development are members of the TGF (transforming growth factors), FGF, BMP, Hedgehog, EDA, Notch and WNT families. The ectomesenchymal expression of MSX1 and PAX9 remains strong from the initiation stage through the bell stage. The closely overlapping expression patterns of PAX9 and Msx1 genes are consistent with a role in epithelial-mesenchymal interactions. Their activity is down regulated at ED16 (Fig. 5).

Bottom Line: Over the course of 500,000,000 years of evolution, many of those structures migrated into the mouth cavity.In addition, the total number of teeth per dentition generally decreased and teeth morphological complexity increased.These interactions involve spatially restricted expression of several, teeth-related genes and the secretion of various transcription and signaling factors.

View Article: PubMed Central - PubMed

Affiliation: University of Athens, Faculty of Biology, Department of Cell Biology and Biophysics, Athens, Greece.

ABSTRACT
The ancestor of recent vertebrate teeth was a tooth-like structure on the outer body surface of jawless fishes. Over the course of 500,000,000 years of evolution, many of those structures migrated into the mouth cavity. In addition, the total number of teeth per dentition generally decreased and teeth morphological complexity increased. Teeth form mainly on the jaws within the mouth cavity through mutual, delicate interactions between dental epithelium and oral ectomesenchyme. These interactions involve spatially restricted expression of several, teeth-related genes and the secretion of various transcription and signaling factors. Congenital disturbances in tooth formation, acquired dental diseases and odontogenic tumors affect millions of people and rank human oral pathology as the second most frequent clinical problem. On the basis of substantial experimental evidence and advances in bioengineering, many scientists strongly believe that a deep knowledge of the evolutionary relationships and the cellular and molecular mechanisms regulating the morphogenesis of a given tooth in its natural position, in vivo, will be useful in the near future to prevent and treat teeth pathologies and malformations and for in vitro and in vivo teeth tissue regeneration.

Show MeSH
Related in: MedlinePlus