Fig. 3

GA transmission reduces GA200 toxicity. A Representative images of fly brains upon expression of polyGA constructs under the control of the orco-Gal4 driver. Brains were stained with an anti-GA antibody. Insets highlight the propagation of GA. B Quantification of GA puncta outside of ORNs (One-way ANOVA + Tukey’s multiple comparisons test; n = 5–6 brains; **P < 0.01 and *P < 0.05). C Representative images of fly brains upon expression of polyGA proteins under the MNC-specific dilp3-Gal4 driver for 10 days. GA400 did not spread from MNCs. Brains were stained with an anti-GA antibody. GA signal in MNCs is outlined in green. Insets highlight propagated GA. D Quantification of GA puncta outside of MNCs (unpaired, two-sided t-test; n = 3–4 brains; *P < 0.05). E Representative images of GA spread in fly brains expressing GA200 in combination with PR100 under the control of orco-Gal4. Insets highlight propagated GA. PR100 increased GA200 spread. F Quantification of GA spread outside of ORNs upon co-expression of PR100 (unpaired, two-sided t-test; n = 7–8 brains; ****P < 0.0001). G Representative images of GA spread in fly brains expressing GA200 in combination with dominant negative shibire (shi^tsDN) under the control of orco-Gal4. Brains were stained with an anti-GA antibody. Insets highlight GA propagation. Shi^tsDN co-expression reduced GA200 spread. H Quantification of GA spread outside of ORNs upon co-expression of shi^tsDN (unpaired, two-sided t-test; n = 6–9 brains; *P < 0.05). I Survival curves of flies that co-express GA200 and shi^tsDN under the control of the pan-neuronal elav-GS driver. GA200 and shi^tsDN co-expression shortened fly lifespan compared to GA200 or shi^tsDN alone (GA200 vs GA200 + shi^tsDN, shi^tsDN vs GA200 + shi^tsDN; log-rank + Bonferroni’s multiple corrections test; n = 150 female flies per genotype; ****P < 0.0001). (A, E, G): Transgenes were induced for 30 days. ORN axons and synaptic terminals are outlined in green. Scale bars in images: 100 µm and insets: 20 µm