Fig. 2. The RAS/MAPK pathway mediates the induction of bracts. (A) rolled¹/rolled^10A leg showing a complete lack of bracts. (B) gap1^B2 leg. Mechanosensory bristles have two or more bracts; chemosensory bristles are not affected. (C-F) Clones of cells mutant for spi ^IIA14, EGFr^4A, Dras^e2F and Draf^EA75. Clones are outlined and cells are marked with forked (C,E,F) or pawn (D). All bristles within clones are bract-less (arrows).