A new finding on DNA repair and aging is reporting at ScienceDaily: "cells in young fruit flies make use of a different mix of molecular DNA-repair mechanisms compared to cells in older flies. ... the reproductive cells of young flies tend to use the rough-and-ready repair processes that do not involve extensive DNA synthesis and do not require a matching DNA template for the repair. As the organisms age, however, the same kind of DNA breaks are repaired primarily by the slower but much more accurate methods that make use of a matching template. These findings raise the question of whether the rapid but risky methods of DNA repair used by cells of young individuals contribute to the accumulation of genetic damage, and perhaps to the aging process itself. Older cells may use the safer repair methods, but they still carry the genetic damage incurred during DNA repair in the fly's 'reckless' youth."

Link: http://www.sciencedaily.com/releases/2006/10/061024010423.htm