Unchanged AZ number and Brp mesoscale arrangement at RIM^R>H NMJs. (A) Exemplar Drosophila RIM^R>H NMJ on abdominal wall muscles 6/7 stained for presynaptic plasma membranes with α-HRP (magenta) and the presynaptic scaffold protein Bruchpilot (Brp^Nc82, green). (B) Summary graphs for the number of Brp puncta (i.e. considered as ‘AZ’) per NMJ 6/7 in abdominal segments A2 and A3, NMJ size and the number of boutons per NMJ in RIM^wt (grey) and RIM^R>H (red; n = 17 NMJs from 5 animals, respectively). (C) Scatter plot of dSTORM localizations of individual AZs recognized by Brp^Nc82 labelled with Cy5 conjugated F(ab′)₂ fragments in RIM^wt and RIM^R>H. (D) Summary graphs for AZ area, the number of Brp localizations (locs.) per individual AZ and Brp localization (loc.) density measured by dSTORM in RIM^wt (grey) and RIM^R>H (red; n = 591 and 712 AZs from 15 NMJs and four animals, respectively). All displayed measurements made with L3 larvae expressing indicated RIM variant as UAS-RIM^X transgene under control of the motor neuron-specific ok6-GAL4 enhancer. See also Supplementary Tables 4 and 5.