Fig. 2. Actin isoform incorporation into filopodia and lamellipodia. Using the ptc-Gal4 driver all six actins were expressed in the embryonic epidermis and amnioserosa, an extraembryonic membrane covering the dorsal region of the embryo, which is displaced by the embryonic epidermis moving dorsally (Jacinto et al., 2002). (A) Diagram illustrating the contact between embryonic epidermis and amnioserosa during stage 14 of embryogenesis. The box indicates the approximate area of scanning shown in the panels below. The row of epidermal cells contacting the amnioserosa (the leading edge cells) display numerous filopodia and some lamellipodia (highlighted by the staining with phalloidin in B'-G'). The amioserosa cells also have many lamellipodia and filopodia contacting neighbouring cells. (B-G) Most actins strongly label the leading edge filopodia and F-actin-rich cellular protrusions within the amnioserosa. Only actin79B (E) did not appear to be strongly incorporated into these but rather filled the cytoplasm more uniformly.