A genome-editing technique can be modified to switch specific genes on and off through 'epigenetic' changes.
The technique, called CRISPR, allows biologists to edit selected DNA sequences, but it does not normally alter the epigenome — the chemical modifications to DNA and associated proteins that regulate gene expression. To target the epigenome, Timothy Reddy and Charles Gersbach at Duke University in Durham, North Carolina, and their colleagues mutated the enzyme used for CRISPR so that it no longer cut DNA, and fused it to part of an enzyme that transfers acetyl groups onto proteins associated with DNA.
The researchers targeted the modified enzyme to proteins near specific DNA sequences, and showed that the added acetyl groups boosted the expression of associated genes. The approach could be used to understand how specific epigenetic changes affect gene expression near the site of chemical modification and farther away, the authors say.
Nature Biotechnol. http://dx.doi.org/10.1038/nbt.3199 (2015)