Effect of food pH on palatability, total consumption, and survival in a taste-defective Poxn mutant and its rescue control (Expt. 5). (A) Effect of food pH and genotype on PER in males (n = 10 flies per group). (B) Effect of food pH and genotype on total consumption in males as measured by radioisotope labeling (n = 6–8 vials per group). Values are mean ± SEM. Labeled means within each series without a common letter differ, P < 0.05. *Different from corresponding control, P < 0.05. (C) Effect of food pH on Poxn mutant lifespan and its control [males, n = 79–82 (control) or 57–61 (Poxn) flies per group; females, n = 95–100 (control) or 47–58 (Poxn) flies per group]. Labeled curves without a common letter differ, P < 0.05. G, genotype; PER, proboscis extension response; Poxn, Pox neuro.