DNA changes linked to height
A study looking at how DNA changes with body size may help scientists to explain why taller individuals tend to have shorter lives.
The paper by the UK’s University of Glasgow and the Norwegian University of Science and Technology is based on wild house sparrows, and shows how changes in DNA that are linked to ageing and lifespan take place as body size gets bigger.
Research was undertaken into telomeres, special DNA structures that all animals have at the ends of their chromosomes. The investigation focused on a population of wild house sparrows on the isolated island of Leka in Norway and was funded by the European Research Council and the Research Council of Norway.
The study found that skeletally bigger house sparrows had shorter telomeres. This relationship was maintained during a period when a selective breeding programme on the island resulted in the sparrows becoming even larger. Likewise, their telomeres became even shorter.
Glasgow’s Professor Pat Monaghan, who supervised the telomere analysis, said: “Growing a bigger body means that cells have to divide more. As a result, telomeres become eroded faster and cells and tissues function less well as a result.
“The reason why the bigger individuals have shorter telomeres might also be related to increased DNA damage due to growing faster. Being big can have advantages, of course, but this study shows that it can also have costs.”
Scientists have found telomeres erode over time, and telomere shortening has been linked to aging and disease risk, including cancer. Having naturally longer telomeres appears to give individuals an advantage when it comes to health and the biological aging process. Yet according to researchers, growing big can mean more telomere loss and faster ageing.
The study is published in the Proceedings of the Royal Society Biological Sciences.
