>
>More evidence that CRONing works, and that it may be able to be
>genetically modulated . . .
>
>
>Thursday December 14 3:49 PM ET
>Gene Mutation Doubles Life Span
>
>By PAUL RECER, AP Science Writer
>
>WASHINGTON (AP) - Mutation of a gene whimsically named ``I'm not dead
>yet'' can double the life span of fruit flies, a laboratory discovery that
>researchers said may lead to drugs to help people live longer and,
>perhaps, even lose weight.
>
>Researchers at the University of Connecticut Health Center have found that
>the life span of fruit flies was extended from an average of 37 days to 70
>days when a gene was modified on a single chromosome. Some flies in the
>study lived 110 days.
>
>The same long-life gene exists in humans, said Dr. Stephen L. Helfand,
>senior author of the study, and ``offers a target for future drug
>therapies aimed at extending life.''
>
>In human terms, a doubled life span would be about 150 years.
>
>Helfand said the gene mutation appears to work by restricting calorie
>absorption on a cellular level - in effect, putting the cells on a diet.
>This raises the possibility, he said, of one day developing a pill that
>would both extend life and control weight.
>
>``From what we know about this gene, that makes perfect sense,'' he said.
>
>Helfand said a key finding of the study, which was appearing Friday in the
>journal Science, is that not only did the fruit flies live longer, but
>they also seemed to maintain a high quality of life.
>
>``It is not an empty or hollow increase in life span. It prolongs active
>adult life, and I think, delays the onset of aging,'' he said.
>
>Some life-extension studies showed that animals tended to trade vigor and
>energy for a longer life, he said.
>
>But the mutant flies ``do well throughout their longer life,'' Helfand
>said. ``By the time that 80 to 90 percent of normal flies are dead, these
>mutants are still doing just fine.''
>
>Blanka Rogina, a co-author of the study, said female flies with the
>mutated genes were able to reproduce throughout life. They had the energy
>for the fruit flies complex courtship ritual and could lay up to 2,000
>eggs in their lifetime, compared with about 1,300 eggs normally, she said.
>
>The long-life gene was named for a comical line - ``I'm not dead yet'' -
>from a Monty Python movie, Helfand said. The gene's name was suggested by
>co-author Robert A. Reenan and has been shortened to ``Indy.''
>
>``In academic circles,'' explained Helfand, ``sophomoric humor, such as in
>Monty Python, is very common.''
>
>There have been other studies that found long-life genes in fruit flies
>and nematodes. There also have been experiments in mice that show calorie
>restriction - a severe diet - can extend life by up to 50 percent.
>
>But Huber Warner, associate director for research into the biology of
>aging at the National Institute of Aging, said the Indy gene discovery is
>more significant because ``it may be a different way to get the same
>effect that caloric restriction achieved in mice and other organisms.''
>
>He said it may be possible to develop a drug that inhibits metabolism in
>the same way as the mutated Indy gene. Such a drug would have to be tested
>extensively in animals to assure that it is safe, Warner said.
>
>``If you wanted to slow metabolism in people, this research suggests that
>this could be a way to do it,'' he said. ``It is strictly theoretical
>right now, but it is a possibility.''
>
>Helfand and his colleagues discovered the livelong gene by chance. He said
>they were screening a strain of fruit flies in another study and found
>that flies were living much longer than normal.
>
>They isolated the Indy gene and then tested it in a number of different
>laboratory fruit fly strains. In all cases, it extended life.
>
>But Helfand said the researchers discovered that if the gene is mutated
>too much, it actually shortens life.
>
>The normal gene is on two chromosomes of the fruit fly. If one of these
>genes is altered, thus reducing the strength of the gene, then the flies
>enjoyed a long life. If both genes were knocked out altogether, said
>Helfand, the flies actually died sooner, perhaps starving to death.
>
>``If we restrict (the gene) a little bit there is a big advantage,'' said
>Helfand. ``But if we make an animal that has only the mutated gene, we
>find that the animal lives a shorter than normal.''
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