The TGF-beta2 isoform is both a required and sufficient inducer of murine hair follicle morphogenesis

Dev Biol. 1999 Aug 15;212(2):278-89. doi: 10.1006/dbio.1999.9325.


Hair follicle development serves as an excellent model to study control of organ morphogenesis. Three specific isoforms of TGF-beta exist which exhibit a distinct pattern of expression during hair follicle morphogenesis. To clarify the still elusive role of these factors in hair follicle development, we have used a combined genetic and functional approach: analysis of hair follicle development in mice with disruptions of the TGF-beta1, 2, and 3 genes was coupled with a direct functional test of the effect of added purified factors on fetal hair follicle development in skin organ cultures. TGF-beta2 null mice exhibited a profound delay of hair follicle morphogenesis, with a 50% reduced number of hair follicles. In contrast to hair follicle development, growth and differentiation of interfollicular keratinocytes proceeded unimpaired. Unlike TGF-beta2-/- mice, mice with a disruption of the TGF-beta1 gene showed slightly advanced hair follicle formation, while lack of the TGF-beta3 gene did not have any effects. Treatment of wild-type, embryonic skin explants (E14.5 or E15.5) with TGF-beta2 protein in either soluble form or slow release beads induced hair follicle development and epidermal hyperplasia, while similar TGF-beta1 treatment exerted suppressive effects. Thus, the TGF-beta2 isoform plays a specific role, not shared by the other TGF-beta isoforms, as an inducer of hair follicle morphogenesis and is both required and sufficient to promote this process.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Embryonic Induction*
  • Epidermis / embryology
  • Hair Follicle / embryology*
  • Mice
  • Mice, Mutant Strains
  • Morphogenesis
  • Organ Culture Techniques
  • Protein Isoforms / genetics
  • Protein Isoforms / metabolism
  • Transforming Growth Factor beta / genetics
  • Transforming Growth Factor beta / metabolism*


  • Protein Isoforms
  • Transforming Growth Factor beta