Developmental mechanisms driving complex tooth shape in reptiles

@article{LandovaSulcova2019DevelopmentalMD,
  title={Developmental mechanisms driving complex tooth shape in reptiles},
  author={Marie Landova Sulcova and Oldřich Zahradn{\'i}{\vc}ek and Jana Dumkov{\'a} and Hana Dosedělov{\'a} and Jan Křiv{\'a}nek and Marek Hampl and Michaela Kavkova and Tom{\'a}{\vs} Zikmund and Martina Gregorovi{\vc}ov{\'a} and David Sedmera and Jozef Kaiser and Abigail S. Tucker and Marcela Buchtov{\'a}},
  journal={Developmental Dynamics},
  year={2019},
  volume={249},
  pages={441 - 464}
}
In mammals, odontogenesis is regulated by transient signaling centers known as enamel knots (EKs), which drive the dental epithelium shaping. However, the developmental mechanisms contributing to formation of complex tooth shape in reptiles are not fully understood. Here, we aim to elucidate whether signaling organizers similar to EKs appear during reptilian odontogenesis and how enamel ridges are formed. 
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OP-ICBJ200116 1..14
Synopsis Among the developmental processes that have been proposed to influence the direction of evolution, the modular organization of developmental gene regulatory networks (GRNs) has shown
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References

SHOWING 1-10 OF 44 REFERENCES
Tooth and scale morphogenesis in shark: an alternative process to the mammalian enamel knot system
TLDR
The results support the fact that no enamel knot, as described in mammalian teeth, can be described in the morphogenesis of shark teeth or scales, however, homologous signaling pathways are involved in growth and morphogenesis with variations in their respective expression patterns.
Signalling networks regulating dental development
Sonic hedgehog regulates growth and morphogenesis of the tooth.
TLDR
The role of Shh is addressed in the developing tooth in mouse by using a conditional allele to remove Shh activity shortly after ingrowth of the dental epithelium and demonstrating that Shh regulates growth and determines the shape of the tooth.
Making a tooth: growth factors, transcription factors, and stem cells
TLDR
Recent progress in the studies of molecular basis of tooth development, adult stem cell biology, and regeneration will provide fundamental knowledge for the realization of human tooth regeneration in the near future.
Unicuspid and bicuspid tooth crown formation in squamates.
  • G. R. Handrigan, J. Richman
  • Biology, Medicine
    Journal of experimental zoology. Part B, Molecular and developmental evolution
  • 2011
TLDR
It is suggested that the early differentiation in squamate unicuspid teeth at cap stage correlates with a more rudimentary tooth crown shape, and the enamel epithelial bulge of the gecko may be more functionally analogous to the secondary enamel knot of mammals than the primary enamel Knot of mammals.
Molecular characterization of dental development in a toothed archosaur, the American alligator Alligator mississippiensis
TLDR
It is demonstrated that the morphologically distinct tooth types in Alligator mississippiensis are distinguishable by differences in their developmental programs, and proposed that such modularity may have been a crucial for adaptive evolution within Amniota, allowing for the progressive modifications to tooth replacement, number, and shape.
...
1
2
3
4
5
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