DNA transfer from mitochondria to the nucleus is an ongoing dynamic process which can cause cancer, a new paper published by Gonville & Caius College Fellow Professor Patrick Chinnery FRCP FMedSci has shown.

Working with colleagues at the University of Cambridge and Queen Mary University of London, the findings were published in Nature this week and change our understanding of how mitochondria cells evolve over time.

Mitochondria are our cells’ batteries and contain their own genetic material called mitochondrial DNA which is only passed from mother to child. They arose billions of years ago from a primitive bacterium which entered the cell and passed on some of its functions through the transfer of DNA.

The DNA transfer was thought to have completed in the ancient past, but now, Patrick and his colleagues have shown this is an ongoing process by studying the genomes of over 66,000 people. The team showed that new chunks of  DNA move from mitochondria to the cell nucleus detected every ~4000 births and at much faster rate in different types of cancer.

Patrick, from the Medical Research Council Mitochondrial Biology Unit and Department of Clinical Neurosciences at the University of Cambridge, says: “Mitochondria are essential for life, and the relationship they forged with the rest of the cell occurred millions of years ago. Our new work shows this relationship continues to develop, and we can measure this in families and in cancers. This usually causes no problems, but sometimes it can go wrong and cause diseases.”

The discovery was “completely unexpected”, Patrick says.

“We really didn’t expect the DNA transfer to be as active as it is. It was a complete surprise to us,” he adds.

“It might also have implications for how we study mitochondria moving forwards. This is a potentially confounding effect that nobody had thought about being a major problem before.”

The research also prompts further questions, and numerous avenues for further research.

“The question of course is what’s the mechanism, how does it happen? We’ve only measured it occurring,” Patrick says.

“We need to work out how it happens and understand what the broader implications for human health and disease. It is also possible that likely that some published work has been incorrectly interpreted (such as the reported transmission of mitochondrial DNA by fathers), because the extent of the DNA transfer was just not known.”

This research was also reported on the University website

The article appears in Nature

Listen to Patrick on the Naked Scientists (geo-restricted), from 17:50.