Injection of GATA4 and GATA5 MOs in endoderm interferes with heart morphogenesis. Top: experimental scheme showing targeted co-injections of MOs and rhodamine-dextran (red fluorescence). The drawing of ventral view of Nieuwkoop and Faber stage 41 embryo  is from http://www.xenbase.org. Cardiac actin/GFP embryos were injected at 32-cell stage with indicated MOs and the fate of injected cells was recorded at st. 41 by rhodamine fluorescence (B, D, F, H, J). A, C, E, G, I: GFP fluorescence was used to observe heart development (cardiac actin/GFP is expressed in all striated muscles, and head muscles are visible in all images), and GFP images were merged with rhodamine images to highlight injected areas. Heart is indicated by arrows, and in specimens where heart was partially injected (C, G), uninjected area is highlighted by an arrowhead. All properly targeted embryos were similarly affected by G4SP and G5SP MOs (n = 8, 10, respectively), but not by C1 MO (n = 7). Ventral views are shown, with anterior at the top.