Fig. 5. PTK7 overexpression does not affect neural crest migration. (A-C) Embryos were injected with 1 ng PTK7 RNA and 50 pg lacZ RNA in one blastomere at the two-cell stage and analyzed for twist expression by in situ hybridization at neurula (A) and tadpole stages (B,C). Light blue lacZ staining marks the injected side. Twist-positive neural crest cells show normal migration at neurula (A) and tadpole stages (B,C). (B) Injected side of a tadpole stage embryo. (C) Uninjected side. (D) Graph summarizing the percentage of twist-expressing embryos injected with 50 pg lacZ RNA, 0.5 ng PTK7 RNA, 0.5 ng myc-tagged PTK7 RNA or 1 ng PTK7 RNA at neurula and tadpole stages. Numbers on the columns indicate the number of injected embryos. (E) Confirmation of PTK7 expression using western blotting (co, uninjected controls) or (F) immunostaining on transverse sections of neurula stage embryos injected with 0.5 ng myc-tagged PTK7 RNA. In F, membrane localization can be detected with a Cy3-coupled myc antibody (left panel). Right panel shows an overlay with the DAPI staining.