University of Bristol: Nature’s photocopiers caught ‘doodling’ – and scientists say it could revolutionise how DNA is written
- Apr 1
- 1 min read
The study, led by the University of Bristol and published in Nature Communications, analyses this curious ‘doodling’ activity, showing for the first time that it can be steered and controlled. The findings not only help shed further light on how genetic information emerges, but could also present exciting new ways of writing long DNA sequences.
Every time a cell divides, it needs to copy its DNA. This job falls to proteins called DNA polymerases – tiny biological machines that read an existing DNA strand and build a matching copy, letter by letter, essentially acting as nature’s photocopiers. It has been known, since the 1960s, that some of these machines can also build new DNA without anything to copy from, in a process scientists nicknamed ‘doodling’. Until now, the sequences produced by doodling have been poorly characterised and this study provides the most detailed assessment to date.
Co-lead author Simeon Castle, who conducted the research as part of his PhD in Engineering Biology at the University of Bristol School of Biological Sciences, said: “We used nanopore sequencing to read the full-length sequences of thousands of DNA molecules that polymerases had created entirely on their own. What we found was far more diverse and complex than anyone had appreciated – from simple two-base repeats to elaborate eight-base motifs, all varying depending on which polymerase was used and the reaction conditions.”
