Effect of disrupting different Rab and Arf GTPases on axonal DCV transport. (A) Small GTPases enriched in the VMAT-specific PB dataset or known to bind JIP3/4/Syd. (B) Representative kymographs showing transport of ILP2-GFP–positive DCVs in third instar larval motor axons in controls, the indicated Rab GTPase mutants, and Arf6/Df. Scale bar: 10 µm. (C) Left, directional distributions derived from B, averaged from the following number of larvae: control 10, Rab32^AR 10, Rab26 8, Rab3/Df 6, Rab8/Df 6, Rab10 8, RabX5 6, and Arf6/Df 11. Right, the logarithmic ratio of retrograde to anterograde peak amplitude for the directional distributions at the left. N.s., not significant (ANOVA, P = 0.522). (D) Representative kymographs showing transport of ILP2-GFP–positive DCVs in motor axons in control larvae and larvae subjected to motor neuron-specific knockdown of Rab11. DCV transport was recorded in second instar larvae for both genotypes. Scale bar: 10 µm. (E) Left, directional distributions derived from D, averaged from seven control and seven Rab11-KD larvae. Right, the logarithmic ratio of retrograde to anterograde peak amplitude for the directional distributions at the left. (F) Representative kymographs showing transport of ILP2-GFP–positive DCVs in motor axons in control larvae and larvae subjected to motor neuron-specific knockdown of Rab1. DCV transport was recorded in first instar larvae for both genotypes. Scale bar: 10 µm. (G) Left, directional distributions derived from F, averaged from four control and three Rab1-KD larvae. Right, the logarithmic ratio of retrograde to anterograde peak amplitude for the directional distributions at the left. Bar graphs in C, E, and G represent mean + SEM. ANOVA (C, right), Student’s t test (E, right; G, right).