Dancing DNA

A new CRISPR/Cas9 DNA labeling technique finds that DNA flails around during the transcription process, increasing its ability to connect distant regions of the genome.

While developing a new technique for labeling individual stretches of DNA, scientists discovered that DNA flails around during transcription, the process in which instructions encoded in genes are used to make RNA.

The technique, termed CARGO, is a variation of the CRISPR/Cas9 gene-editing tool used to seek out and replace specific DNA sequences in the genome with other DNA sequences. CARGO can precisely tag any stretch of DNA with fluorescent molecules to track its three-dimensional location and movements, according to a study published Jan. 24 in Science.

Researchers used CARGO, which they say could answer many questions about the genome or gene expression, to learn that the act of transcription agitates DNA strands, increasing the ability to bring distant regions of the genome together.

DNA that wriggles during transcription was entirely unexpected, says senior author Joanna Wysocka, PhD, professor of developmental biology and of chemical and systems biology.

“It’s just one example of what we and others can now learn by using CARGO to label specific DNA regions.”