Specific transforming growth factor-beta subtypes regulate embryonic mouse Meckel's cartilage and tooth development

Dev Biol. 1994 Mar;162(1):85-103. doi: 10.1006/dbio.1994.1069.


Members of the transforming growth factor-beta (TGF-beta) superfamily have emerged as critical regulators for cell growth and differentiation. Whereas the different TGF-beta subtypes are equipotent in the majority of biological assays using cell lines cultured in vitro, there are indications that in more complex systems involving epithelial-mesenchymal interactions, the TGF-beta subtypes differ in their biological activities. To test the hypothesis that TGF-beta subtypes specifically regulate either Meckel's cartilage or tooth morphogenesis, we designed experiments to compare loss of function effects of TGF-beta 1, TGF-beta 2, and TGF-beta 3 subtypes using a serumless, chemically defined medium to culture embryonic mouse E10 (42-44 somite pairs) mandibular explants. The major effect of loss of function resulting from abrogation of TGF-beta 1 using antisense treatment resulted in a 20% increase (P < 0.05) in chondrocyte number, a decrease in extracellular matrix, and dysmorphology of the rostral region of Meckel's cartilage. Exogenous TGF-beta 1 provided indistinguishable recovery to the normal phenotype. TGF-beta 2 antisense treatment produced a threefold enlargement (P < 0.05) of tooth organs and advanced their development to the cap stage. TGF-beta 2 provided recovery to the normal phenotype (e.g., reduced tooth size and development to the bud stage), whereas TGF-beta 1 or TGF-beta 3 polypeptides had no effect. TGF-beta 3 antisense treatment resulted in a reduction of approximately 15% in the length of Meckel's cartilage. We interpret these results to suggest that TGF-beta 1 functions to regulate the number of chondrogenic cells, the amount of extracellular matrix, and the rate of developmental assembly of the rostral to posterior segments in forming Meckel's cartilage. TGF-beta 2 appears to regulate tooth size and stage of development without affecting cartilage. TGF-beta 3 appears to regulate Meckel's cartilage size without altering tooth size or shape. The results are discussed in terms of the regulatory functions of the TGF-beta subtypes during embryonic craniofacial morphogenesis.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Base Sequence
  • Cartilage / embryology*
  • Cartilage / growth & development
  • Culture Techniques
  • Female
  • Immunohistochemistry
  • Mandible / embryology*
  • Mandible / growth & development
  • Mice
  • Molecular Sequence Data
  • Morphogenesis
  • Oligonucleotides, Antisense
  • Tooth / embryology*
  • Tooth / growth & development
  • Transforming Growth Factor beta / classification
  • Transforming Growth Factor beta / physiology*


  • Oligonucleotides, Antisense
  • Transforming Growth Factor beta