Tag Archives: stephen helfand

Parasitic DNA proliferates in aging tissues

As mice age, cells in tissues such as the liver and skeletal muscle lose control over rogue sequences of DNA called “retrotransposable elements,” according to new research in the journal Aging. The elements, which may undermine health, could proliferate in old mice and were also abundant in cancerous tissue. A low-calorie diet, however, restrained their advance.

PROVIDENCE, R.I. [Brown University] — The genomes of organisms from humans to corn are replete with “parasitic” strands of DNA that, when not suppressed, copy themselves and spread throughout the genome, potentially affecting health. Earlier this year Brown University researchers found that these “retrotransposable elements” (RTE’s) were increasingly able to break free of the genome’s control in cultures of human cells. Now in a new paper in the journal Aging, they show that RTEs were increasingly able to break free and copy themselves in the tissues of mice as the animals aged. In further experiments the biologists showed that this activity was readily apparent in cancerous tumors, but that it also could be reduced by restricting calories. (more…)

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Aging erodes genetic control, but it’s flexible

In yeast at least, the aging process appears to reduce an organism’s ability to silence certain genes that need to be silenced. Now researchers at Brown University who study the biology of aging have shown that the loss of genetic control occurs in fruit flies as well. Results appear online in the journal Aging.

PROVIDENCE, R.I. [Brown University] — Biologists at Brown University have found a way to measure the effects of aging by watching the ebb and flow of chromatin, a structure along strands of DNA that either silences or permits gene expression. In several newly published experiments they show that gene silencing via chromatin in fruit flies declines with age. (more…)

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