Reproductive Competence Reduces Life Span

Science Signaling  11 Nov 2008:
Vol. 1, Issue 45, pp. ec386
DOI: 10.1126/scisignal.145ec386

Life span is influenced by many factors, including nutrition, metabolism, chemosensation, and reproduction, but the molecular links among these factors are not yet clear. Wang et al. demonstrate that the reproductive system affects longevity in the nematode Caenorhabditis elegans by modulating fat metabolism. The increased longevity observed in animals in which the germline stem cells had been genetically or mechanically ablated was accompanied by a decrease in the amount of lipids stored in intestinal cells. Conversely, the decreased life span of animals in which germline stem cells were induced to overproliferate was associated with increased fat storage in intestinal cells. These effects of the germ line on fat storage were mediated by the triglyceride lipase K04A8.5 in the intestinal cells. Expression of K04A8.5 increased in the absence of germline stem cells and decreased with germline stem cell overproliferation. In adult animals with reduced insulin signaling, K04A8.5 expression increased and fat storage decreased in intestinal cells. Reducing K04A8.5 function by RNA interference partially suppressed the increase in life span associated with reduced insulin signaling. These results indicate that both insulin signaling and signals from the gonad affect fat metabolism in intestinal cells. A Perspective by Xie discusses these results in the context of other recent studies addressing the influence of the reproductive system on longevity.

M. C. Wang, E. J. O'Rourke, G. Ruvkun, Fat metabolism links germline stem cells and longevity in C. elegans. Science 322, 957-960 (2008). [Abstract] [Full Text]

T. Xie, Burn fat, live longer. Science 322, 865-866 (2008). [Summary] [Full Text]