Figure 4. αE-catenin is required for incisor epithelium invagination.

(a–d) αE-catenin is normally expressed throughout the dental epithelium at E12.5 and E13.5, but expression is absent in Ctnna1^cKO. (e–l) Histological analysis and 3D reconstruction show smaller and abnormally shaped tooth germs at E13.5 and developmentally arrested epithelia at E14.5 in Ctnna1^cKO (f,h,j,l) when compared with littermate controls (e,g,i,k). Dotted lines outline the tooth germ epithelium in a–h, and yellow arrowheads indicate the tooth germ epithelium in i–l. VL, vestibular lamina. Scale bar, 25 μm (a–d); 100 μm (e–h); 200 μm (i–l).