Figure 2. Stress resistance and lifespan enhanced by Imd downregulation in flies developed at 25°C. (A) RT-PCR analyses of imd and AMP genes in Imd pathway. Using total RNAs of 2-day-old male flies developed at 25°C, gene expressions in hetero (imdP/+) and homozygous (imdP) mutants were normalized with those of wild-type (+/+: 1 fold) and then, were averaged with SEM. (B) The survival curve for starvation stress using 2-day-old male flies (p-value: log-rank test). (C) Increased stress resistance of 2-day-old imdP mutant flies from the wild-type flies (+/+: 0%). The median survival times of flies under each stress (starvation, oxidation or heat) were calculated from the several survival curves (B) and then, the changed percentages are represented as average ± SEM after normalization with the median times of wild-type flies (Table 1). (D) The lifespan of adult male flies between the wild-type and imdP mutants. (E) Increased mean lifespan of imdP mutant flies. Percent changes of mean lifespan are indicated as average ± SEM normalized by wild-type lifespan days (Table 1), which were calculated from the several lifespan curves (D). (F) Changes of weight and nutritional contents between 2-day-old wild-type and imdP mutants male flies. After fresh weight per fly was measured (mg/fly), the nutrient contents were normalized by fresh weight of fly (μg/mg). The data represent average ± SEM normalized by nutrient contents of wild-type flies (Table 1).