The insects have their own equivalent of a key human ageing gene called WRN, researchers have discovered.

Experts hope that studying the gene in fruit flies will help them understand important aspects of the human ageing process.

Flies with damage to the gene share key features with people afflicted by the rapid ageing condition Werner syndrome.

In particular, the flies have unstable DNA and their chromosomes are often altered.

The scientists, led by Dr Lynne Cox from Oxford University, showed that DNA became rearranged, with genes being swapped between chromosomes.

Genes are stretches of DNA that provide the coded instructions for making proteins, while spiralling strands of packaged DNA make up the chromosomes in every cell.

In patients with Werner syndrome, this genomic instability leads to cancer.

Cells from sufferers of the disorder are highly sensitive to a drug often used to treat cancers. Flies with the damaged gene are killed by very low doses of the drug, the scientists found.

Dr Cox said: "We study a premature human ageing disease called Werner syndrome to help us understand normal ageing. The key to this disease is that changes in a single gene (called WRN) mean that patients age very quickly.

"Scientists have made great progress in working out what this gene does in the test tube, but until now we haven't been able to investigate the gene to look at its effect on development and the whole body. By working on this gene in fruit flies, we can model human ageing in a powerful experimental system."

Fellow researcher Dr Robert Saunders, from the Open University, said: "This work shows for the first time that we can use the short-lived fruit fly to investigate the function of an important human ageing gene. We have opened up the exciting possibility of using this model system to analyse the way that such genes work in a whole organism, not just in single cells."

The research is funded by the Biotechnology and Biological Sciences Research Council.

Professor Nigel Brown, of the BBSRC, said: "Fruit flies are already used as a model for the genetics behind mechanisms that underlie normal functioning of the human body and it is great news that this powerful research tool can be applied to such an important area of study into human health."