Fig. 3. FoxF function is necessary for TVC migration. (A-F) Embryos electroporated (A,C-F) or injected (B) with Mesp>GFP to mark the B7.5 lineage (green). The red channel detects the fluorescent background of the Ciona embryo. (A) Wild-type embryo with normal anterior TVC and posterior tail muscle positions (lateral view). (B) Embryo co-injected with Mesp>GFP and FoxF morpholino. Anterior B7.5 cells fail to detach from their sister muscle cells and to migrate into the trunk (ventral view). (C) Mesp>GFP co-electroporated with Mesp>FoxF:VP16. All B7.5 lineage cells have migrated into the trunk (ventral view). (D) Mesp>GFP co-electroporated with Mesp>FoxF:WRPW. All B7.5 cells remain in the tail. (E) Mesp>GFP co-electroporated with Mesp>Ets:VP16. All B7.5 cells migrate into the trunk (lateral view). (F) Mesp>GFP co-electroporated with Mesp>Ets:VP16 and Mesp>FoxF:WRPW. Inhibited TVC migration occurs that is comparable to that observed with FoxF:WRPW alone. (G) The five distinct classes of migration phenotypes. (H,I) Proportions of embryos distributed among the five phenotypic classes in each condition, including EtsVP/FoxFW and EtsW/FoxVP epistasis tests; color coding is as in G.