Fig. 7. Patterns of Dll, Exd, Hth and Sal accumulation in pb5Scr5/pb1Scr4 mutants. (A) Scanning electron micrograph showing a transformation of the proboscis into an antenna in a pb5Scr5/pb1Scr4 mutant. Note the absence of claws or pulvillae. (B) Wild-type labial discs express low levels of Hth (green) and no Sal (blue). (C) pb5Scr5/pb1Scr4 mutant labial discs express domains of Dll (red), Exd (green) and Sal (blue) that resemble those in the antennae. (For reference, wild-type labial disc expression patterns of Dll and Exd are shown in Fig. 2B,C.) (D,E) In the labial discs of pb1Scr4/pb5Scr5 mutants, Sal expression (blue) is localized to cells expressing both Dll (red) and Hth (green, shown with arrows in D).