NMII ^HC /Zip facilitates changes of presynaptic F-actin upon mechanical severing of larval axons. (A) mNGMA-labeled presynaptic actin at NMJs from live NMII^HC/Zip⁶⁵⁹⁴⁷ larvae with intact brains (left) or upon severing of the brain/axotomy (right). (B–D) Analyses of the mNGMA fluorescence, as well as round and linear F-actin assemblies. Box-and-whisker graphs were used to represent the results of the area and fluorescence intensity of the individual presynaptic actin structures. Whiskers represent 10^th to 90^th percentile, while the rest of the data points are shown as individual values. The y axis in these graphs represents log₁₀, to capture the broad distribution of the individual values. In bar graphs with linear Y axis, error bars represent the SEM. N in bar graphs—NMJs; N in box and whiskers—individual actin assemblies. ns—not significant, *P < 0.05 and ***P < 0.001 upon the unpaired, nonparametric Mann–Whitney test. Error bars represent the SEM. Scale bar—2 µm. See Table S1 for detailed genotypes and N.