Old Chromosomes

As people age they start to shrivel and shrink and so, apparently, do their chromosomes. Senescence – the technical term for getting old – occurs at the cell as well as organism level. And researchers have discovered that chromosomes inside senescing cells become more compact. The computationally modeled chromosomes pictured, for example, represent a normal replicating cell (left) and a senescent one (right). Although this compaction appears to close down the genome – indeed many genes become silenced – certain genes are activated during the process. Senescence marks the end of a cell’s ability to reproduce, and while this means that tissues of elderly people can’t repair as well as those of youngsters, it also provides an inherent protection against cancer – where cells divide uncontrollably. Understanding how cells transition to senescence and which genes they turn off or on could thus aid research into cancer prevention and, on the flip side, tissue regeneration.

Written by Ruth Williams

Ruth Williams

Writer

Ruth is a freelance science journalist based in the US. She's a regular correspondent for The Scientist, and her work has appeared in The Lancet, Nature, Scientific American Mind, BBC Focus and elsewhere. Twitter @rooph

Website

• Image from work by Steven W. Criscione and Marco De Cecco, and colleagues
• Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI, USA
• Image copyright is held by the authors, and licensed under a CC BY-NC attribution
• Published in Science Advances, February 2016