Fig. 3. Wing veins deviate toward nearby mew^- clones. mew^M6 clones were generated in a sog misexpression background (sog^EP7) using FLP/FRT-mediated recombination and were scored by the marker forked (f). (A) A dorsal mew^M6 clone adjacent to the L2 vein displaces the vein towards the clone. The broken black line indicates the normal trajectory of the L2 vein. (B) A small mew^M6 clone adjacent to a distal region of L2 has a similar vein deviating effect. (C) A mew^M6 clone between veins L3 and L4 alters the course of the L3 vein. The distance between the tips of L2 and L3 is increased as a function of L3 being displaced posteriorly (arrow) towards the mew^M6 clone. The broken black line indicates the approximate location where the L3 vein would normally form. (D) A mew^M6 clone that straddles the L2 vein by several cells on each side of the vein does not significantly disrupt the course of the vein. (E) A mew^M6 clone adjacent to the posterior crossvein induces formation of ectopic vein material between the normal vein and the clone. (F) Ventral mew^M6 clones adjacent to veins have no effect. Broken red lines indicate the limits of dorsal clones, broken purple lines indicate ventral clones.