ANCIENT BACTERIA AND LONGEVITY. “The gerontogenes are classified as lifespan regulators, mediators, effectors, housekeeping genes, genes involved in mitochondrial function, and genes regulating cellular senescence and apoptosis. In this review we demonstrate that the majority of the genes as well as genetic and epigenetic mechanisms that are involved in regulation of longevity are highly interconnected and related to stress response.” The mitochondrion originated from an engulfed bacteria.
http://www.tandfonline.com/doi/abs/10.4161/cc.28433