Fig. 7. Ectodermal structural defects in Msx2-Cre;β-Cat^c/c embryos. (A-H) Toluidine Blue staining (A,B,E,F) and TEM analyses (C,D,G,H) on E10.5 coronal sections (A-D) and E12.5 transverse sections (E-H) reveal that the mutant surface epithelium is thinner (compare D to C, H to G). In addition, the ectoderm and endoderm maintain close contact in wild-type GTs (A,C), whereas the two layers appear to be separated in mutants (asterisks, D). (I-N) Immunostainings indicate an absence of β-catenin (J), an upregulation of plakoglobin (arrows, L) and normal E-cadherin expression in mutant ectoderm (N). (O-R) Immunostainings showing a total absence of K14 expression (R) but unchanged p63 expression (P) in E12.5 mutant ectoderm. Scale bars: 50 µm in I-N; 100 µm in O-R.