When Lef1 was misexpressed in ectodermal cells in transgenic mice, extra invaginations of epithelium were formed, and this resulted in aberrant formation of hair follicles and tooth like structures in the lip-furrow area. This indicates that Lef1 is associated with the ability of the epithelium to trigger hair and tooth morphogenesis in the underlying mesenchyme (Zhou et al, 1995).
The role of Lef1 has been analysed in tissue recombination experiments between knockout mutant and wild type tissues and it was shown that although the gene is expressed throughout tooth morphogenesis and shifts from epithelium to mesenchyme, expression is only needed in the epithelium prior to bud stage (Kratochwil et al, 1996). Lef1 presumably regulates an epithelial signal that is required for mesenchyme determination. The expression of BMP-4 in dental epithelium and the expression of Msx1 in mesenchyme were unaffected in Lef1 knockout mouse suggesting that the epithelial signal triggered by Lef1 involves a different pathway.
|Jackson Mouse Genome Database||Transgene Database||OMIM|