Fig. 1.

Extracellular Notum reduces Wg ligand levels and trans-synaptic signaling. (A) Representative image of muscle 4 NMJ co-labeled for CRISPR-generated Notum:HA (Notum, green) and synaptic label anti-Discs Large (DLG, red). (B) Representative NMJ bouton images of extracellular anti-Wingless labeling (Wg, green) co-labeled with synaptic marker anti-horseradish peroxidase (HRP, red) in w¹¹¹⁸ background control versus Notum^KO null mutant and UH1-Gal4/+ transgenic control versus UH1>Notum:RNAi. (C) Representative synaptic bouton images of anti- Fz2-C (green) at the NMJ (HRP, red) in w¹¹¹⁸ and Notum^KO. (D) Representative images of postsynaptic nuclei co-labeled with anti-Fz2-C (green) and nuclear label DRAQ5 (blue) in UH1/+ control versus UH1>Notum:RNAi. (E) Quantified Wg fluorescent intensities in all four genotypes normalized to control. (F) Quantified Fz2 fluorescent intensities at the NMJ synaptic terminal (left) and postsynaptic nuclei (right) in Notum^KO and UH1>Notum:RNAi normalized to controls (w¹¹¹⁸ and UH1/+). *P≤0.05, ***P≤0.001.