Fig. 3. Loss of autophagy leads to synaptic connections with aberrant neuronal partners.

a–c Neurons postsynaptic to control (a), atg6 mutant (b), and atg18 mutant (c) R7s are labeled with trans-Tango (see Methods for full genotypes; magenta = postsynaptic neurons, green = CadN, Me = medulla, Lo = lobula, Lop = Lobula plate). Arrowheads show postsynaptic neurons labeled for autophagy-deficient R7s but not for control R7s. Repeated three to five times independently with similar results. d Number of postsynaptic neurons per optic lobe for control, atg6 mutant, and atg18 mutant R7s based on trans-Tango-labeled cell body counts. n = 10 optic lobes per condition. One-way ANOVA and Tukey’s HSD as post-hoc test **p < 0.01, ***p < 0.001. Error bars denote mean ± SEM. e Examples of aberrant neuronal partners of autophagy-deficient R7s, with individual neurons pseudo-colored in white. f Schematic of dendritic and axonal arborization of aberrant neuronal partners (redrawn and adapted based on Golgi impregnations from Fischbach and Dittrich⁴⁶). g Number of each aberrant neuronal partners per optic lobe from 1-week-old fly brains. Note that only ∼10% of R7s are mutant for atg6 and trans-Tango labeling is dependent on synaptic strength between partners and progressively increase through age. See Methods for detailed Drosophila genotypes used to perform trans-Tango experiments. Source data are provided as a Source Data file.