Fig. 1.

GRNs (Gustatory receptor neurons) in the labral sense organ (LSO) and Gr-GAL4 drivers expressed.

(A) Gr-GAL4 driven GFP reporter expression in the LSO. (B) Results of combinations of the Gr2a-GAL4 driver and the indicated Gr-GAL4 drivers. The position of the LSO is marked as a box on the schematic of a fly head on the right. All Gr-GAL4 expressing neurons exist as a pair in the LSO, and only one neuron of each pair is shown here. (C) Axonal projections of GRNs in the LSO to the subesophageal zone (SEZ). The brain neuropil is counterstained with the monoclonal antibody nc82 (magenta). The asterisks indicate projections due to labellar gustatory receptor neurons. On the right is a schematic of a fly head and GRNs in the LSO. (D) The three GRNs that exist in the LSO and the Gr-GAL4 drivers expressed. Scale bars, 10 μm.