DCX-EMAP organizes the ultrastructure of the MO. (A) Representative confocal images (lateral view of leg receptors) showing the localization of DCX-EMAP and its various mutants as indicated. Scale bar, 5 µm. Genotypes: 1. DCX-EMAP-gal4,uas-cd4-tdtom/+; DCX-EMAP^KI. 2. DCX-EMAP-gal4,uas-cd4-tdtom/uas-gfp-DCX-EMAP; DCX-EMAP^KO. 3. DCX-EMAP-gal4,uas-cd4-tdtom/uas-gfp-ΔDCX1/2; DCX-EMAP^KO. 4. DCX-EMAP-gal4,uas-cd4-tdtom/uas-gfp-ΔDCX1; DCX-EMAP^KO. 5. DCX-EMAP-gal4,uas-cd4-tdtom/uas-gfp-ΔDCX2; DCX-EMAP^KO. 6. DCX-EMAP-gal4,uas-cd4-tdtom/uas-gfp-ΔHELP; DCX-EMAP^KO. 7. DCX-EMAP-gal4,uas-cd4-tdtom/uas-gfp-ΔWD40; DCX-EMAP^KO. (B) Representative intensity line profiles of GFP-DCX-EMAP and its various mutants along the distal–proximal axis of the outer segment in the leg receptors (DCX-EMAP^KO background). Two short bars indicate the regions where the fluorescence signals for the TB and MO were measured. (C) Statistical quantification of the intensity of GFP-DCX-EMAP and the mutants (n = 9, 13, 9, 9, 15, and 12 cells) in the MO and TB of the leg receptors. (D) Representative confocal images (lateral view of leg receptors) showing the localization of four DCX-EMAP mutants (wild type background). Scale bar, 5 µm. Genotypes: 1. DCX-EMAP-gal4,uas-cd4-tdtom/uas-gfp-ΔDCX1/2. 2. DCX-EMAP-gal4,uas-cd4-tdtom/uas-gfp-ΔDCX2. 3. DCX-EMAP-gal4,uas-cd4-tdtom/uas-gfp-ΔHELP. 4. DCX-EMAP-gal4,uas-cd4-tdtom/uas-gfp-ΔWD40. (E) Statistical quantification of the intensity of GFP-DCX-EMAP and its mutants shown in D (n = 7, 7, 8, and 9 cells) in the MO and TB of the leg receptors. (F) Representative ET slices images of leg receptors (lateral view) in ΔDCX1/2^rescue (left panel) and ΔWD40^rescue (right panel). Scale bar, 300 nm. Also see Videos 8 and 9. (G) Statistics quantification of the area of the EDMs observed in the ET slice images of the leg receptors in wild type (n = 4 cells), DCX-EMAP^KO (n = 3 cells), ΔDCX1/2^rescue (n = 4 cells) and ΔWD40^rescue (n = 3 cells). (H) Crawling tests of DCX-EMAP^KO (n = 11 flies), DCX-EMAP^rescue (DCX-EMAP-gal4/uas-gfp-DCX-EMAP; DCX-EMAP^KO, n = 10 flies), ΔDCX1/2^rescue (DCX-EMAP-gal4/uas-gfp-ΔDCX1/2; DCX-EMAP^KO, n = 15 flies), ΔDCX1^rescue (DCX-EMAP-gal4/uas-gfp-ΔDCX1; DCX-EMAP^KO, n = 5 flies), ΔDCX2^rescue (DCX-EMAP-gal4/uas-gfp-ΔDCX2; DCX-EMAP^KO, n = 7 flies), ΔHELP^rescue (DCX-EMAP-gal4/uas-gfp-ΔHELP; DCX-EMAP^KO, n = 15 flies), and ΔWD40^rescue (DCX-EMAP-gal4/uas-gfp-ΔWD40; DCX-EMAP^KO, n = 14 flies). Also see Video 10. In C, E, G, and H, data are presented as mean ± SD with scattered data points. In C and E, for comparison between different strains, two-sided unpaired Student’s t test was used. For comparison between TB and MO from the same cell, two-sided paired Student’s t test was used. **, P < 0.01; ***, P < 0.001; n.s., no significance.