Fig. 7. The impact of Dpp-insensitive mutant modules is ameliorated in multimodular brk reporters. Wing discs stained for lacZ to visualize reporter expression. The module number and organization are depicted schematically. (A) Wild-type L13 reporter. (B,D,F) In fragments containing individual modules (see Fig. 4 for nomenclature; mutant modules indicated in superscript), disruption of SMM sites results in expression throughout the wing pouch. (C,E,G) By contrast, multimodular L13 reporters containing the same lesions do not show derepression in the medial region (compare with B,D,F, respectively). (H) L13^M3+M7/8/9, which contains two mutant modules shows significant expansion of lateral expression but continues to be repressed medially, where Dpp activity is highest. The narrow central stripe of expression corresponds to the AP boundary where pMad levels are lower (Tanimoto et al., 2000).