
Fig. 2. Notch1 and Delta1 are expressed in the neural fold of quail embryos during neural crest formation. (A-C) Slug expression in the premigratory neural crest cells (arrowheads). At the one-somite stage, Slug expression is barely detectable in whole-mount preparation (but see Fig. 3E). (D-F) Pdgfr
expression in the premigratory cranial crest cells (arrowheads). An arrow in E indicates somite expression. (G-I) Delta1 expression in the epidermal ectoderm (arrowheads). Arrow in G indicates strong expression in presomitic mesoderm. Asterisk in I indicates expression in the neural plate. (J-L) Broad expression of Notch1. Arrowheads in J indicate the boundary of the neural plate and the epidermal ectoderm.