Fig. 5. The role of L1 and PSA-NCAM in the superficial migration. (A) Staining with antibody against L1. Only some axons at the region of the superficial migration are positive for L1 (arrowheads). (B) Whole-mount in situ hybridization for TAG-1 on explants incubated for 2 days in medium with Fab fragments of polyclonal antibody against L1. The trajectories of the migrating cells are normal. (C,D) Whole-mount in situ hybridization for TAG-1 on explants from L1-null (C) and wild-type (D) animals. The migration of TAG-1-positive cells is normal even in L1-deficient animals. (E) Staining with antibody against PSA-NCAM. PSA-NCAM was detected on the cell bodies of the migrating cells. (F) Whole mount is situ hybridization for TAG-1 on explants treated with EndoN during the culture. The TAG-1-positive cells migrated normally when PSA was cut. Scale bars: 50 µm in A,E; 500 µm in B-D,F.