Figure 7. The HMN7B mutation, but not the Perry syndrome mutations, disrupts axonal transport.

(A) Kymographs from live-cell time-lapse imaging of LAMP1-RFP in DRG neurons at 2 DIV expressing wild-type (WT), ΔCAP-Gly, CC1, HMN7B (G59S) or Perry syndrome (G71R & Q74P) p150^Glued. Images were acquired at 366 ms per frame for 2.2 minutes; scale bars for the x and y-axes represent 10 μm and 20 seconds, respectively. Kymographs show the first 180 frames, full movies shown in Movies S4 and S5. (B) Quantification of vesicle motility from the kymographs showed that only the HMN7B (G59S) mutation and CC1 disrupt motility. >575 vesicles were counted per condition. Mean ± SEM, n=5–8 neurons per condition, *P<0.05, **P<0.01 compared to wild-type, one-way ANOVA Bonferroni post test. (C–E) Individual tracks from the kymographs were analyzed. (C) Mean anterograde and retrograde instantaneous velocities ± SD, n>800 instantaneous velocities per condition per direction. Also see Figure S7. Quantification of the number of pauses per track (D) and motility switches per track (E). Mean ± SEM, n>23 vesicles per condition, **P<0.01 compared to wild-type, one-way ANOVA Bonferroni post test.