Figure 2

Ectopic miR-34 overexpression inhibited γ lobe pruning in MB neurons.

Confocal images show γ lobes of MB neurons in wild-type flies (a–c,g–i) and flies that were for ectopic miR-34 overexpression (one copy of miR-34 in (d–f,j,k); two copies of miR-34 in l) driven by GAL4-OK107 (a–h,j,k) or GAL4-201Y (i and l). FasII staining (magenta) and mCD8::GFP (GFP) expression (green) of MB neurons reveal the morphology of the larval-specific γ lobes (arrowheads) and α and β lobes (arrows) at various time points after puparium formation (APF). In MB neurons of wild-type flies (a–c and g–i), the process of pruning larval-specific γ lobes (arrowheads) appeared to be initiated in the γ lobes themselves, where the lack of FasII staining was observed from 6 h APF (asterisks, a) to the near completion of axon pruning at 18 h APF (arrowheads). The developing α and β lobes were observed from 24 h APF onward (arrows, c,g–i). By contrast, in the MB neurons with ectopic miR-34 overexpression, a significant fraction of larval-specific γ lobes was remained at 18–24 h APF (double-arrowheads, e,f,i), and aberrant axonal braches (most likely γ lobe-derived) were located adjacent to the developing α and β lobes at 36-48 h APF (double-arrowheads, j,k). Fly genotypes are listed in Supplemental Table 2. Scale bar: 10 μm for all panels.