Figure 2. Atg16 is required for autophagy in larval fat and adult brain cells.

(a) Lipidated, autophagosome-associated Atg8a (Atg8a-II) is missing and the selective autophagy cargo p62 accumulates in Atg16^d129 and Atg16^d67 mutant larval lysates, similar to Atg7^d77 mutants. These phenotypes are rescued by Atg16-HA expression in Atg16^d67 mutants. (b,c) Starvation-induced punctate LTR staining is blocked in homozygous Atg16^d129 (b) and Atg16^d67 (c) mutant fat body cells that are marked by GFP expression, compared to neighboring GFP-negative control cells. (d–f) Ultrastructural images of fat cells in starved L3 larvae. Autophagosomes (asterisks) and autolysosomes (arrowheads) are seen in control (d) and genetically rescued (f) animals, unlike in Atg16^d67 mutant fat body cells (e). (g–i) Endogenous p62-positive protein aggregates (green dots) accumulate throughout the brain of Atg16^d129 (h) and Atg16^d67 (i) animals compared to control brain (g). (j–l) Ultrastructural analysis of 20-day-old brains reveals the presence of large protein aggregates (p) in Atg16^d67 mutant neurons (k), which are absent from control (j) or genetically rescued (l) animals.