Fig. 1. Axial-level-dependent downregulation of N-cadherin protein, but not mRNA, in the dorsal NT is correlated with loss of noggin transcripts. (A-C) N-cadherin immunoreactivity. Arrowheads point to the dorsal NT of a 25-somite-stage embryo that expresses N-cadherin immunoreactivity opposite the segmental plate (C), but lacks the protein in the region facing epithelial somites (B) and dissociated somites (A). Arrows in B depict the onset of NC emigration from a N-cadherin-deficient dorsal NT. (D-F) N-cadherin mRNA showing no change in dorsal NT along similar axial levels. (G) Axial-dependent downregulation of noggin mRNA coincides with a similar pattern of N-cadherin disappearance. Abbreviations: DS, dissociated somites; ES, epithelial somites; M, myotome; N, notochord; NT, neural tube; Scl, sclerotome; SP, segmental plate. Scale bar: 80 µm.