Serosal window closure fails after Tc-DocRNAi. Both embryos express nuclear-localized GFP (nGFP) ubiquitously and are shown in lateral aspect with anterior left and dorsal up. The movie shows early development of Tribolium including the last round of cell division in the uniform blastoderm followed by another round only in the germ rudiment (embryo and amnion). Left: wild type development showing the flattening of the posterior pole (primitive pit) followed by the formation of the posterior and later anterior amniotic folds. While the embryo invaginates, the border between the amnion and serosa forms the closing serosal window. Finally, the amnion and serosa detach from each other, releasing the embryo and the amnion into the yolk where they undergo germ band extension. For a schematic view of early development see main text Figure 8. RNAi Right: Tc-DocRNAi embryo showing normal cell division and invagination. However, closure of the serosal window slows down and finally stalls, tethering the head at a ventral position. Image stacks were acquired every 10 min at 24°C and are shown as maximum intensity projections at each time point. The wild type and RNAi embryo are stage matched and shown at the same developmental rate, with elapsed time in hours and minutes indicated. See also main text Figure 4.