Figure 3.

Possible relationships between autophagy and DNA degradation in Drosophila oogenesis. The diagram depicts how autophagy might play a role in the DNA degradation process based on the reduced TUNEL staining phenotype observed in dying mid-stage egg chambers of DmAtg1 and DmAtg7 mutants. Autophagy could positively regulate the activities or subcellular localization of cell-autonomous nucleases (that generate TUNEL-reactive fragments) and thereby enhance DNA degradation. Alternatively, autophagy may negatively regulate the activity of lysosomal nuclease DNAseII (that generates TUNEL non-reactive DNA ends), and thereby suppress or delay DNAseII-mediated DNA degradation. Finally, autophagy could sustain the high ATP levels that are required for display of engulfment signals, including lysophosphatidylcholine (come-get-me) and/or phosphati-dylserine (eat-me).