Blockage of synaptic transmission in a subset of tutl -positive neurons significantly affected navigational pattern in response to tactile stimuli. (A-C) Larvae carrying GMR91F06-GAL4 and UAS-CD4-tdGFP were double-stained with anti-GFP (green) and anti-Tutl antibody (red). Note Tutl protein is widely expressed in the nervous system and is predominantly localized to the neuropils of the CNS (B and C). (D-F) Larvae carrying tutl-GAL4 and UAS-CD4-tdGFP were double-stained with anti-GFP (green) and anti-Tutl antibody (red). Scale bars: 50 μm. (G) Navigational behaviors of 3rd-instar larvae in which UAS-shits was driven by GMR91F06-GAL4, tutl-GAL4, or GMR60G12-GAL4. The performance of larvae at restrictive temperature (32°C, black bars) was compared to that of same-genotype larvae at permissive temperature (22°C, white bars). *p < 0.05, **p < 0.01, ***p<0.005, “ns” indicates p>0.05, t-test. Number in each bar indicates the number of larvae tested in the experiments. (H) Navigational pattern of larvae in which UAS-TeTxLC was driven by GMR91F06-GAL4 or tutl-GAL4, was examined. *p < 0.05, **p < 0.01, ***p<0.005, “ns” indicates p>0.05, t-test. Error bars represent SEM.