Tspan18 knockdown inconsistently enhances neural crest migration. (A–F) Embryos unilaterally electroporated with ContMO (A,B) or TS18MO (C–F) were processed by whole mount in situ hybridization for Sox10 at 8 or 9 somites (A,C,D, dorsal view, anterior embryo half; A′,C′,D′, construct targeting; B,E,F, midbrain transverse sections at the level indicated). Neural crest migration is unaffected by ContMO (A,B, arrows). TS18MO-electroporated neural crest cells migrated normally in most embryos (C,E, arrows), but was enhanced in 28.1% of embryos (D,F, arrowheads). (G) Bar graph represents the frequency of embryos with enhanced or normal migration.