Control of epidermal autophagy by TOR signalling. (A) Epidermis of third instar larvae expressing the autophagosome marker GFP-Atg8a together with constructs for up- or down-regulating the autophagy pathway in the epidermis. Healthy epidermis contains few autophagosomes, but artificially activating autophagy through overexpression of Atg1 or blocking TOR signalling leads to accumulation of autophagosomes. (B) Higher magnification of the areas marked by magenta boxes in (A). 