P-DNA ELEMENT MOVEMENT IN SOMATIC-CELLS REDUCES LIFE-SPAN IN DROSOPHILA-MELANOGASTER - EVIDENCE IN SUPPORT OF THE SOMATIC MUTATION THEORY OF AGING

Evidence is presented in support of the hypothesis that P DNA element movement in somatic cells of Drosophila melanogaster induces genetic d amage that significantly reduces lifespan. The lifespan of D. melanoga ster males was significantly reduced by the somatic movement of a sing le P element in the presence of P[ry(+) Delta 2-3](99B) transposase. I n addition, the P[ry(+) SaII](89D) repressor of P[ry(+) Delta 2-3](99B ) somatic transposase was observed to reduce the effect of P element m ovement on lifespan. Finally, the frequency of somatic-cell chromosome breakage was significantly increased in neuroblasts of males with som atically active P elements. These results show that lifespan in D. mel anogaster is decreased with increased somatic genetic damage from DNA- element movement. Although this conclusion does not confirm that trans posable element movement is a cause of natural senescence, this conclu sion is clear evidence in support of a close relationship between soma tic genetic damage and aging.