(A) Double labeling of 891-Gal4 (magenta, CD8-tdTOMATO) and sugar-sensing GRNs (green, CD4-GFP) indicates that axons of sugar-sensing GRNs anatomically overlap with neural processes in 891-Gal4. Shown is SEZ as in Fig 1D, where gustatory axons project. Single optical slice (2 μm) in region of maximum overlap is shown. (B) 891-Gal4 axons (magenta, synaptotagmin::eGFP) and sugar-sensing GRNs (green, CD8-tdTOMATO) overlap in the SEZ. Single optical slice (2 μm) in region of maximum overlap is shown. (C) Reconstitution of GFP in flies expressing spGFP(1–10) in 891-Gal4 (co-labeled with CD8-tdTOMATO, magenta) and spGFP(11) in sugar-sensing GRNs (Gr5a-LexA). Scale = 20μm.