Fig. 1. Striped epidermal expression of GMA reveals cell shape during morphogenesis. UAS-GMA expression driven by either enGAL4 (A,D-G) or prdGAL4 (B,C) demonstrates cell shape in epidermal stripes, as well as in some amnioserosal cells (arrows in B,C) that continue these stripes dorsally. (D-G) Frames from a time-lapse video (Movie 1 at http://dev.biologists.org/supplemental/) showing that epidermal stripes generally meet in register at the dorsal midline. However, mismatches are observed (small arrowheads in D-F) and in some cases suturing along the dorsal midline continues for a substantial distance prior to mismatch resolution (E,F, arrows indicate progression of dorsal closure).