Fig. 5. Ventral hair placodes and dermis are lacking in the absence of β-catenin in the En1 lineage. (A) Whole-mount in situ hybridization with a Ptch1 anti-sense mRNA probe reveals ventral hair follicle placodes at E14.5 in control embryos. (B) Ventral skin hair follicle placodes are absent in En1Cre; R26R; β-cat^lof mutants. (C,D) Sections of E16.5 embryos stained with Hematoxylin and Eosin (H&E). (E-J) X-gal-stained sections of E16.5 embryos. (E,F) The ventral dermis is present in the control (E) but is absent from the skin of mutant fetuses (F). (G-J) Higher magnification images of boxed areas in E and F. (E,G,I) In control embryos, lineage-labeled cells are visible in the sternum, dermis and epidermis, but not in the ribs. (F,H,J) In the mutants, lineage-labeled cells are present in the sternum and epidermis, and the sternum is wider. Scale bars: in C,D, 2 mm; in E,F, 500 µm; in G-J, 200 µm.