Strain-specific effects of parental age on offspring in Drosophila melanogaster

Maternal age is generally known to be negatively correlated with the lifespan of offspring in several animal models including yeast, rotifers, flies, and possibly in humans. However, several reports have shown positive effects of parental age on offspring lifespan. Thus, there was a need to investigate further the inconsistent results on the effect of parental age on lifespan. In this study, the effects of parental age on offspring fitness and lifespan were examined by using Drosophila melanogaster. The lifespan of offspring from old parents was significantly increased compared with that of the young counterparts in the Canton-S (CS) strain but not in other D. melanogaster strains, such as Oregon-R (OR) and w¹¹¹⁸. To find out why the lifespan is increased in the offspring from old parents in CS flies, fitness components that could modulate lifespan were examined in CS flies. Egg weight and body weight were reduced by parental aging and the offspring of old fathers or old mothers developed faster than that of the young. In addition, the offspring of old parents had increased resistance to oxidative and heat shock stresses. However, reproductive capacity, mating preference, and food intake were unaffected by parental aging. These results indicate that parental aging in CS strain D. melanogaster has beneficial effects on the lifespan and fitness of offspring. The presence of strain-specific manner effects suggests that genetic background might be a significant factor in the parental age effect.