Figure 3. Stress responses after knockdown of octopamine receptor OAMB and serotonin receptor 5-HT_1A in IPCs.

A Reduction of octopamine receptor OAMB level in IPCs increases resistance to starvation (seen by extended survival). OAMB was diminished in IPCs by driving two different OAMB-RNAi lines with Dilp2-Gal4. The Dilp2-Gal4>OAMB-RNAi GD flies showed about 50% percent increase of median lifespan compared with controls (***p<0.001 to both parental controls; Log rank test, Mantel-Cox; n = 120 for each genotype). We used the OAMB-RNAi GD lines hereafter for all other experiments. In an earlier study it was shown that 5-HT_1A knockdown decreased starvation resistance [22]. B Reduction of octopamine receptor OAMB or serotonin receptor 5-HT_1A levels in IPCs increases resistance to oxidative stress induced by feeding male flies 20mM paraquat in standard food. Both receptor knockdowns result in flies that display significantly increased survival under paraquat exposure (***p<0.001 to both parental controls, Log rank test, Mantel-Cox; n = 60–90 for each genotype).