Loss of klp-7 rectifies the microtubule polarity switch phenotype in the lin-17 mutant. (A) Confocal images and schematics of neuronal polarity phenotype in lin-17(0) and lin-17(0);klp-7(0). (B) The percentage of PLM neurons with polarity reversal phenotype due to altered klp-7 or ptrn-1 levels in Wnt mutants (lin-17, lin-44, dsh-1mig-5). N = 4–5 independent replicates; n (number of neurons) = 20–208. (C) Kymographs from EBP-2::GFP movies (Video 1) showing the microtubule growth events in lin-17(0) and lin-17(0);klp-7(0). The green and magenta traces represent microtubules of plus-end-out and minus-end-out polarity, respectively. (D and E) The histogram shows the fraction of plus-end-out (P) and minus-end-out (M) microtubules (D) obtained from C and the percentage of PLM processes with microtubules oriented in either a unipolar or mixed manner (E). N = 7–8 independent replicates, n (number of neurons) = 19–52. Ant, anterior; Pst, posterior. (F) Kymographs of GFP::RAB-3 reporter (jsIs821) in lin-17(0);klp-7(0) background showing the events of anterograde (green arrow trace) and retrograde (magenta arrow trace) movement. The white arrows show the stationary particles. (G and H) The number of movement events of GFP::RAB-3 vesicles as obtained from F. Anter, anterograde; Retr, retrograde. N = 3–4 independent replicates; n (number of neurons) = 18–26. For B and E, ***, P < 0.001; Fisher’s exact test. For D, G, and H, *, P < 0.05; ***, P < 0.001; ANOVA with Tukey’s multiple comparison test. Error bars represent SEM.