Figure 2.

Autophagic structures accumulate in a specific pattern in the Drosophila eye disc. (A to A’’’) Anti-Atg5 antibody staining shows a nearly uniform Atg5 accumulation in the eye disc, with highest levels in the areas of prospective head cuticle (yellow arrows). Green foci in the differentiation zone (DZ) correspond to Atg5-positive structures (early autophagosomal structures). Pictures were taken by conventional fluorescence microscopy. (B to B’’’) Optical sectioning by a semiconfocal microscopy reveals an unequal distribution of Atg5-positive autophagic structures in the eye disc, predominantly in the MF and DZ. (C to C’’’’) Confocal microscopy image showing anti-Atg5-positive autophagic structures. Ato (red) is specific marker for labeling the MF. (D to D’’’) Anti-Atg8a antibody staining indicates autophagic structures, using optical sectioning of a semiconfocal microscopy. Green foci indicate autophagosomal and autolysosomal membranes. Atg8a-positive structures accumulate most abundantly along and behind the MF (indicated by a white arrow). (E to E’’’) mCherry-Atg8a reporter gene driven by ey-Gal4(II) is expressed almost in the entire eye field. Red foci label autophagosomes and autolysosomes. mCherry-Atg8a-positive structures accumulate most evidently in the DZ. Images in panels A to E’’’ are positioned as antenna parts are up; bars: 100 µm; samples were prepared from L3W larvae. MF: morphogenetic furrow. Hoechst staining indicates nuclei. Animals were maintained at 25°C.