Fig. 6.

SE in the neural plate border is converted into the NE fate in the Grhl3 mutant embryos. (A–C′) Lineage analysis of Grhl3 expression in Grhl3^+/cre-nZ (A–C) and Grhl3 ^{cre-nZ/cre-nZ} (A′–C′) embryos at E8.25 with X-gal staining. Transverse sections counterstained with eosin (C, C′). (D, E, E′) Immunohistochemical analyses of whole embryo (D) and frozen section (E, E′) at E8.25 in wild-type (D), Grhl3^cre-nZ/+ (E), and Grhl3^{cre-nZ/cre-nZ} (E′) embryos. β-gal (GRHL3, green), N-cadherin (magenta), TROMAI (blue), and DAPI (cyan). β-gal-positive cells express N-cadherin in addition to TROMAI within the SE layer in Grhl3 heterozygous mutant embryos (E). β-gal-positive cells are mislocalized within the NE tissue in Grhl3 null embryos (E′, white arrowheads). (F, F′) Immunohistochemical analyses of whole embryos at E8.5 in wild-type (F) Grhl3^{cre-nZ/cre-nZ} (F′). DAPI (green), N-cadherin (blue), and TROMAI (magenta) in F and F′. N-cadherin-negative and TROMAI-negative cells correspond to uncommitted neural border progenitor cells (green; arrows in F and F′). (G–M′) Immunohistochemical analysis with a neural crest marker, SOX9 using whole-mount embryos (G–J′) and frozen sections (K–M′) in Grhl3^cre-nZ/+ (G–M) and Grhl3^{cre-nZ/cre-nZ} (G′–M′). SOX9 (yellow), β-gal (GRHL3, green), TROMAI (magenta) and nuclei (DAPI, blue). Regarding cell behaviors of the SOX9-positive neural crest, a clear difference was not detected between heterozygous and homozygous mutant embryos. Scale bars: 300 μm in A, A′; 200 μm in D–F′; 100 μm in C, C′, G–J′; 20 μm in K–M′.