Fig. 6.

Schematic drawings of the Tc-sog and Tc-dpp RNAi phenotypes. (A) Tc-sog RNAi. The neurogenic ectoderm (green) is absent. Dorsal cell fates occupy domains along the AP axis: Dorsal serosal cells (red) are present in a broad band anterior to the germ rudiment, and amniotic cells (dark blue) are present along the anterior margin of the germ rudiment and in the primitive pit. Dorsal amnion is absent. The serosa/germ rudiment border is straight and is located at the position of the dorsal border in WT. The presumptive mesoderm (dotted line with arrow) is correspondingly shorter along the AP axis. (B) WT. Dorsal serosal cells and amniotic cells are localized to the dorsal side. Neurogenic ectoderm and mesoderm are present. The germ rudiment/serosa border is oblique and runs from a dorsal, posterior position to a ventral, anterior position. (C) Tc-dpp RNAi. Dorsal serosa and amnion are absent. Mesoderm and an anterior serosa (orange) are present. The germ rudiment/serosa border is straight and located at the position of the WT ventral border. The rest of the embryo consists of neurogenic ectoderm. pp, primitive pit.