Fig. 7. Gbb and α₂δ-3 have related functions in presynaptic organization.

a–c Representative z-projections of boutons of the indicated genotypes labeled with Brp (magenta) and DGluRIII (green). Scale bar: 2 µm. d Quantification of the Brp+ synapse density. n is the number of boutons scored. e Schematic of α₂δ-3 subunit of a voltage-dependent Ca²⁺ channel. Stars mark the locations of the stop codons in α₂δ-3^DD106 and α₂δ-3^DD196 alleles. f–h Representative deconvolved z-projections of boutons of the indicated genotypes labeled with anti-Brp. Scale bar: 1 µm. i Quantification of single planar Brp ring diameters. j Quantification of the percentage of planar Brp rings in multimers in boutons. For Brp ring analyses, n is the number of boutons scored. k–m Representative z-projections of boutons of the indicated genotypes labeled with DVGLUT (green) and HRP (magenta). Scale bar: 2 µm. n Quantification of the percentage of boutons exhibiting properly localized synaptic vesicles. n is the number of NMJs scored. o Quantification of integrated DVGLUT intensity compared to proper controls. n is the number of boutons scored. p Quantification of Brp+ synapse density. q Quantification of the percentage of boutons exhibiting properly localized synaptic vesicles. r Quantification of Brp+ synapse density. n is the number of boutons scored. s Quantification of the percentage of boutons exhibiting properly localized synaptic vesicles. n is the number of NMJs scored. For the bar graph, error bars are mean ± SEM. For all box-and-whisker plots, error bars are min and max data points, and the center line indicates the median. Individual data points are displayed as dots. n.s. not significantly different. *p < 0.05; **p < 0.01; ***p < 0.001. All tests are nonparametric Kruskal–Wallis one-way ANOVAs on ranks followed by Dunn’s multiple comparison test.