Chapter 10. Affecting Tooth Morphology and Renewal by Fine-Tuning the Signals Mediating Cell and Tissue Interactions

  1. Gregory Bock Organizer and
  2. Jamie Goode
  1. Irma Thesleff,
  2. Elina Järvinen and
  3. Marika Suomalainen

Published Online: 11 JUN 2007

DOI: 10.1002/9780470319390.ch10

Tinkering: The Microevolution of Development: Novartis Foundation Symposium 284

Tinkering: The Microevolution of Development: Novartis Foundation Symposium 284

How to Cite

Thesleff, I., Järvinen, E. and Suomalainen, M. (2006) Affecting Tooth Morphology and Renewal by Fine-Tuning the Signals Mediating Cell and Tissue Interactions, in Tinkering: The Microevolution of Development: Novartis Foundation Symposium 284 (eds G. Bock and J. Goode), John Wiley & Sons, Ltd, Chichester, UK. doi: 10.1002/9780470319390.ch10

Author Information

  1. Developmental Biology Research Program, Institute of Biotechnology, PO Box 56, FIN-00014 University of Helsinki, Viikinkaari 9, Helsinki, Finland

Publication History

  1. Published Online: 11 JUN 2007
  2. Published Print: 8 JUN 2006

Book Series:

  1. Novartis Foundation Symposia

Book Series Editors:

  1. Novartis Foundation

ISBN Information

Print ISBN: 9780470034293

Online ISBN: 9780470319390

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Keywords:

  • epithelial-mesenchymal interactions;
  • tooth morphogenesis;
  • enamel;
  • tooth replacement;
  • tooth regeneration;
  • Wnt;
  • FGF;
  • BMP;
  • Activin;
  • stem cells

Summary

Interactions between the epithelial and mesenchymal tissue components of developing teeth regulate morphogenesis and cell differentiation, and determine key features of dentitions and individual teeth such as the number, size, shape and formation of dental hard tissues. Tissue interactions are mediated by signal molecules belonging mostly to four conserved families: transforming growth factor (TGF)β, Wnt, fibroblast growth factor (FGF) and Hedgehog. Recent work from our laboratory has demonstrated that tooth morphology and the capacity of the teeth to grow and renew can be affected by tinkering with these signal pathways in transgenic mice. The continuous growth of the mouse incisors, as well as their subdivision into the crown and root domains, is dramatically altered by modulating a network of FGF and two TGFβ signals, bone morphogenetic protein (BMP) and Activin. This network is responsible for the regulation of the maintenance, proliferation and differentiation of epithelial stem cells that are responsible for growth and enamel production. On the other hand, the activation of the Wnt signalling pathway induces continuous renewal of mouse teeth (which normally are not replaced), resembling tooth replacement in other vertebrates. It can be concluded that the different dental characters are quite flexible and that they are regulated by the same conserved signal pathways. These findings support the suggestions that tinkering with the signal pathways is the key mechanism underlying the morphological evolution of teeth as well as other organs.