Lack of correlation between mitochondrial reactive oxygen species production and life span in Drosophila

The free radical theory of aging proposes that mitochondrial production of reactive oxygen species (ROS) determines the rate of aging. Supporting this hypothesis, longer-lived species produce fewer ROS than shorter-lived ones, and calorically restricted rodents live longer and produce fewer ROS than controls. We studied such correlation in Drosophila melanogaster in caloric restriction and in mutant flies overexpressing the mitochondrial adenine nucleotide translocase (ANT). Caloric restriction extended life span, but there was no significant difference in mitochondrial ROS production compared with controls. ANT overexpressers had significantly lower ROS production (because they had lower membrane potential), but their life span was not extended compared to wild type. Our results show two examples in which mitochondrial ROS production and life span are not correlated.