Researchers in the UK have developed a powerful new technique to show how the environment affects our DNA.

The technique can be used to map all of the 'epigenetic marks' on the DNA of a single cell.

The method is set to boost the understanding of embryonic development and could enhance clinical applications like cancer therapy and fertility treatments.

It even has the potential to reduce the number of mice currently needed for genetic research.

'Epigenetic marks' are chemical tags; proteins that mark DNA and act as a kind of cellular memory.

They do not change the DNA sequence but record a cell's experiences onto the DNA, which allows cells to remember an experience long after it has faded. Placing these tags is part of normal development; they tell genes whether to be switched on or off and so can determine how the cell develops. Different sets of active genes make a skin cell different from a brain cell, for example. However, environmental cues such as diet can also alter where epigenetic tags are laid down on DNA and influence an organism's long-term health.

The new research, published in Nature Methods, offers a new single-cell technique capable of analysing DNA methylation – one of the key epigenetic marks – across the whole genome.

It treats the cellular DNA with a chemical called bisulphite, and the treated DNA is then amplified and read on high-throughput sequencing machines to show the location of methylation marks and the genes being affected.

“Our work provides a proof-of-principle that large-scale, single-cell epigenetic analysis is achievable to help us understand how epigenetic changes control embryonic development,” neuroscientist Dr Gavin Kelsey said.

“The application of single-cell approaches to epigenetic understanding goes far beyond basic biological research.

“Future clinical applications could include the analysis of individual cancer cells to provide clinicians with the information to tailor treatments, and improvements in fertility treatment by understanding the potential for epigenetic errors in assisted reproduction technologies,” he said.