Synaptic marker immunoreactivity at Dscam2 mutant NMJs and results from the Dscam2 interactor candidate screen. (A–D) Representative images of dlg immunoreactivity in control (A), Dscam2^null (B), Dscam2A (C), and Dscam2B (D) in MN6/7-Ib (Ib) and MNSNb/d-Is (Is). Scale bar, 10 µm. (E and E’) Quantification of diameter of anti-dlg immunoreactivity surrounding boutons. Data shown as mean ± SEM, n indicated in graph; one-way ANOVA; groups compared with Tukey's post-test. ***, P < 0.001; ****, P < 0.0001. (F–I) Representative images of anti-Syt1 immunoreactivity in control (F), Dscam2^null (G), Dscam2A (H), and Dscam2B (I) in Ib and Is. Scale bar, 10 µm. (J and J’) Quantification of anti-Syt1 immunofluorescence (IF) intensity relative to control. Data shown as mean ± SEM; n indicated in graph; one-way ANOVA; groups compared with Tukey’s post-test. (K) Quantification of EJP amplitude in different combinations of genotypes. Stock numbers listed in Materials and methods. Data shown as mean ± SEM; n indicated in graph. Kruskal-Wallis test; groups compared with Dunn’s post-test. **, P < 0.01. IF, immunofluorescence.