Extended Data Figure 5: Shortening of the Dpp gradient by posterior morphotrap expression.
From: Dpp spreading is required for medial but not for lateral wing disc growth
a, Scheme of morphotrap expression in the posterior compartment (using hh::Gal4) in dppd8/d12 mutant wing discs rescued with eGFP::Dpp. b, Posterior morphotrap expression in the rescue background results in strong eGFP signal in the first three cell rows of the posterior compartment due to eGFP::Dpp accumulation; after three cell rows the eGFP fluorescence signal drops. c, p-Mad staining in a dppd8/d12 mutant wing disc rescued with eGFP::Dpp. d, p-Mad staining in a dppd8/d12 mutant wing disc rescued by eGFP::Dpp and expressing morphotrap in the posterior compartment. Note that the eGFP::Dpp accumulation (marked by a yellow line) directly overlaps with the observed p-Mad signal. e, The average p-Mad profiles show that the p-Mad gradient range directly depends on the range of Dpp spreading (error bars are s.d.). f, dppd8/d12 mutant wing discs rescued with eGFP::Dpp expressing morphotrap in the posterior compartment stained for Sal and Omb (for control discs see Extended Data Fig. 3a). The A/P boundary is marked by a dotted red line and the range of the eGFP::Dpp accumulation is marked by a dotted yellow line. In this condition the domain width of both targets is strongly reduced. The Sal domain directly collapses onto the eGFP::Dpp accumulation domain. However, Omb, which can be activated at lower Dpp signalling levels, shows a slightly wider distribution. We hypothesize that this is again due to morphotrap-stabilized eGFP::Dpp being dragged into the posterior compartment (as discussed in Extended Data Fig. 3). Intensity profiles of the enlarged regions are plotted to the right. g, Representative dppd8/d12 mutant wing discs rescued with eGFP::Dpp expressing morphotrap in the posterior compartment stained for Brk at the indicated time points (79–12 h AEL). In this condition the medial region shows strongly reduced growth (compare to Fig. 5a–f). However, the growth dynamics of the lateral domain are similar to the lateral growth observed in control wing discs (right).
