Ephrin-A2 is expressed by recently delaminated and migratory neural crest cells in the somite. (A, B, C) Cross sections through stage 14–18 embryos stained with ephrin-A2 antibody (green) and DiI (red), by prelabeling neural tubes prior to neural crest migration. (D, E, F) Ephrin-A2 antibody labeling. Ephrin-A2 is associated with the surfaces of neural crest cells that have recently delaminated (A, D), initiated entry into the somites (B, E), and migrated into the rostral half sclerotome (C, F). nt, neural tube.