Transposable elements as a factor in the aging of Drosophila melanogaster.

We have considered the hypothesis that transposable elements may contribute to the aging process through somatic mutation. We have presented evidence to suggest that at least two elements, Copia and 412, are capable of somatic activity in adult Drosophila tissue. A strain harboring a third transposable element, P, was produced that showed eye color mosaicism and reversion to wild phenotype (red eyes) as a result of somatic and germ line transposition. A high-fat diet, known to accelerate aging, increased the frequency of eye color mosaicism and red eyes. We induced life span shortening by artificially activating somatic transposition of P elements, and the extent of reduction in life span was similar in both sexes. These data are consistent with the notion that some aspects of the age phenotype may be caused by mutational activity of transposable elements in somatic tissues. The hypothesis is readily tested in other organisms, including humans. It offers new dimensions in the understanding and management of age-associated changes.