Expression patterns of DR5rev:GFP in wild-type and putative smo1-1 smo1-2 embryos. A, DR5rev:GFP distribution in wild-type embryos at the heart stage. B to F, DR5rev:GFP distribution in putative smo1-1 smo1-2 embryos. Note that DR5rev:GFP signal was absent at the apical part of the ball-shaped smo1-1 smo1-2 embryos (B and C), exhibited ectopic expression in suspensor cells (D), accumulated in one point at the apical part of the embryo (E), or was evenly distributed at the apical outer layer of the embryo proper (F). Bars = 50 μm.