Research Paper Volume 10, Issue 4 pp 622—631

Stress resistance and lifespan enhanced by downregulation of antimicrobial peptide genes in the Imd pathway

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).