Figure 2. Notum requires the GAGs of glypicans to inhibit Wingless signalling.
a-c, Ectopically expressed dNotum-V5 does not suppress Senseless expression in the absence of dlp (b) or dally (c). Although dNotum is only expressed in a vertical band along the A-P boundary, it spreads along the whole A-P axis. d, Ectopic dNotum represses Senseless expression in dlp mutants that express Dlp-CD8 (tubulin promoter). e, Expression of an RNAi transgene against sulfateless in the posterior compartment prevents dNotum-V5 (expressed from dpp-lexA lex-op-notum-V5) from being retained at the cell surface and from suppressing Senseless expression. Wingless signalling is still suppressed in the anterior compartment. f, Accumulation of dNotum-V5 is reduced at the surface of dlp dally double mutant tissue (GFP-negative).