Fig. 4.

Molecular marker analyses in CAG-Dkk1 and Dkk1^−/− mutant embryos. (A) A schematic construct of the CAG-Dkk1 transgene. (B–C′, L) The gross appearances of wild-type (B, C), CAG-Dkk1 (B′, C′), and Dkk1^−/− (L) embryos at E8.5 (B, B′, L) and E18.5 (C, C′). (D, P) Transverse sections of embryos. Each section plane is represented by a corresponding line in the scheme in CAG-Dkk1 (D) and Dkk1^−/− (P). (E–K′, Q–X) Immunohistochemical analyses with frozen sections of the wild-type (E–K), CAG-Dkk1 (E′–K′), and Dkk1^−/− (Q–T) and with whole embryos of the wild-type (U, W) and Dkk1^−/− embryos (U′, V, W′, X) at E8.5 (E–K′, Q–T), E8.25 (U–V) and E8.75 (W–X). SOX2 (E, E′, Q), N-cadherin (F–G′, R), Tuj1 (H, H′), E-cadherin (I, I′), TROMAI (J–K′, S–V), and KERATIN17/19 (W, X) merged with nuclei staining (TOTO-3; magenta in E-H′, J–K′, Q–T; blue in U–X). (M–O′) Whole-mount in situ hybridization in the wild-type (M–O) and Dkk1^−/− embryos (M′–O′) at E8.5. Lateral and frontal views of Sox2 expression (M–N′) with sectional views and lateral views of Tfap2c expression with their frontal views (O, O′). Scale bars: 3 mm in C, C′; 300 μm in B, B′, L–O′, W–X; 100 μm in E–F′, H, H′, J, J′, Q–U′; 10 μm in I, I′, K, K′.