Dscam2^null mutants exhibit PI3K-deficient phenotypes. (A–C) Genetic interactions between Dscam2 and the PI3K enhancer Centaurin Gamma 1A (CenG1A). Quantification of corrected evoked (A) and spontaneous (B) potential amplitude as well as quantal content (C) for control, CenG1A^EY01217/+, Dscam2^null/+, CenG1A^EY01217/+;Dscam2^null/+, CenG1A^{EY01217/EY01217;}Dscam2^null/null, and CenG1A^{EY01217/EY01217}; Dscam2^null/null (EJP’ and quantal content analyzed with one-way ANOVA, groups compared with Tukey’s post-test; mEJP analyzed with Kruskal-Wallis test, groups compared with Dunn’s post-test). (D–E’) Representative images of HRP immunoreactivity (magenta, D and E) and anti-mCherry (red, D’ and E’) from the PIP₂ reporter (PLCδPH-mCherry) in control (OK6-GAL4/⁺; UAS-PLCδPH-mCherry/⁺) and Dscam2^null (OK6-GAL4/⁺; Dscam2^null, UAS-PLCδPH-mCherry/Dscam2^null). Scale bar, 5 µm. (F and F’) Quantification of PLCδPH-mCherry immunofluorescence intensity per bouton normalized to control in Ib (F) and Is (F’; unpaired Student’s t test). (G–H’) Representative images of HRP immunoreactivity (magenta, G and H) and anti-mCherry (red, G’ and H’) from the PIP₂ reporter (PLCδPH-mCherry) in control (OK6-GAL4/⁺; UAS-PLCδPH-mCherry/+) and CenG1A^EY01217 (CenG1A^EY01217, OK6-GAL4/CenG1A^EY01217; UAS-PLCδPH-mCherry/⁺). Scale bar, 5 µm. (I and I’) Quantification of PLCδPH-mCherry immunofluorescence. Intensity per bouton normalized to control in Ib (I) and Is (I’; Mann-Whitney rank-sum test). (J and K) Quantification of EJP’ in control (black) and Dscam2^null (red) in the presence of a titration of the PI3K-inhibiting drugs Wortmannin (J; n = 7–13) and LY294002 (K; n = 9–15); two-way ANOVA omnibus reveals significant differences overall between control and Dscam2^null after application of Wortmannin and LY294002. Data shown as mean ± SEM; n indicated in graph. *, P < 0.05; **, P < 0.01; ***, P < 0.001; ****, P < 0.0001 for all panels. IF, immunofluorescence.