Fig. 2. Wing veins are poorly defined in ßPS^- mutant clones. mys^XB87 clones were generated in a sog misexpression background (sog^EP7) using FLP/FRT-mediated recombination and were recognized by the marker multiple wing hair (mwh). (A) Dorsal clones that cross over or lie adjacent to longitudinal veins, such as L4 and L5 induce the formation of veins with diffuse boarders (arrows indicate limits of the vein phenotype). Veins in these regions are less compact, less pigmented and wider than normal veins. (B) A higher magnification view of the wing in A showing that veins broaden within two cell diameters from the border of mys^XB87 clones, but are unaffected when displaced by greater distances from the clones (e.g. compare vein phenotypes at red versus black arrows). (C) Two dorsal clones running over L3 induce thickened and diffuse vein sections. (D) A ventral clone adjacent to L5 has no effect on vein formation. Broken red lines indicate the limits of dorsal clones; broken purple lines indicate ventral clones; + indicates heterozygous or wild-type tissue; – indicates homozygous mutant clones.