Figure 4. Post developmental caspase activation, and persistence in the adult of cells that experienced developmental caspase activity at Drosophila anterior midgut.

Biosensor fluorescence of anterior midgut of (a) Newly eclosed Gal80^ts–temperature sensitive(ts) CaspaseTracker flies raised at 18°C. The thermosensitive Gal80 (Gal80^ts) conditionally represses Gal4 at 18°C; biosensor is functional “Off” during development. (b) Newly eclosed 18°C raised (ts) adult CaspaseTracker flies were then shifted to 30°C for 10 days. Gal80^ts cannot repress Gal4 at 30°C; biosensor is functional “On” at the 10-day period. (c) Newly eclosed tsCaspaseTracker flies raised at 30°C; biosensor is functional “On” at the development. (d) Newly eclosed 30°C raised (ts) adult CaspaseTracker flies were shifted to 18°C for 10 days. Gal80^ts represses Gal4 at 18°C; biosensor is functional “Off” at the 10-day period.