Fig. 3.

GA spreads in a repeat length-dependent manner from an independent neuronal population. a-c Representative images of 5-days-old fly brains from (a) control flies, expressing only the Optic Lobe (OL)-Gal4 driver, (b) flies expressing GA100 or (c) GA200 in the OLs for 3 days and probed with an anti-GA antibody. GA200 also spreads more than GA100 from this brain region. The same settings were used while imaging the GA signal across genotypes. EGFP with a nuclear localization signal was co-expressed to identify the cells targeted by the OL-Gal4 driver. d Quantification of GA puncta detected in the central brain outside of the targeted cells after expression of the indicated constructs for 3 days. Flies expressing only the driver (a) were used to control for unspecific binding of the anti-GA antibody (**P < 0.001 and *P < 0.05; One-way ANOVA, n = 6–8). Insets of the indicated areas are shown to facilitate visualization. Scale bars in images and insets are 100 um and 10 um, respectively