Fig. 2.

Spreading is increased in longer GA repeat proteins. a-c Representative images of 5-days-old fly brains expressing mCherry (a), GA100-mCherry (b) and GA200-mCherry (c) from Olfactory Receptor Neurons (ORNs) for 3 days. The same settings were applied to all genotypes while imaging their mCherry signals. Spreading is greater for GA200-mCherry than for GA100-mCherry. The mCherry signal was detected using its fluorescence as read-out. Flies expressing only mCherry (a) served as negative control to ensure that mCherry does not spread by itself. d Quantification of mCherry puncta detected in the central brain outside of ORNs across genotypes per brain after induction for 3 days (***P < 0.001 and **P < 0.01; One-way ANOVA, n = 4–5). e-g Representative images of 5-days-old fly brains expressing GA100 (f) or GA200 (g) in ORNs for 3 days and probed with an anti-GA antibody. GA200 spreads more than GA100. The same settings were used while imaging the GA signal across genotypes. Flies expressing only the driver (e) served to control for unspecific binding of the anti-GA antibody. Unspecific binding to trachea (blue asterisks) and the lamina of the optic lobes (red asterisks) was observed. h Quantification of GA puncta detected outside of the ORN boundaries across genotypes per brain after induction for 3 days. (**P < 0.01 and *P < 0.05; One-way ANOVA, n = 5–9). The boundaries of the ORN axons and synaptic terminals are highlighted with a solid green line. Insets of the indicated areas are shown to facilitate visualization. Scale bars in images and insets are 100 um and 10 um, respectively