3D maps reveal 'genomic origami'

Researchers, including an Indian-origin scientist, have created a three-dimensional (3D) map of human genomes to reveal their folding patterns and hidden switches that can turn on deadly disease causing genes.

The map revealed a structural basis for gene regulation - a kind of "genomic origami" that allows the same genome to produce different types of cells.

The researchers set out to identify the folding pattern called loops in the human genome. Loops form when two bits of DNA that are far apart in the genome sequence end up in close contact in the folded version of the genome in a cell's nucleus.

"More and more, we are realising that folding is regulation," said study co-first author Suhas Rao, a researcher at the Baylor College of Medicine in the US.

"When you see genes turn on or off, what lies behind that is a change in folding. It's a different way of thinking about how cells work," Rao added.

For the study, the researchers used a technology called "in situ Hi-C" to collect billions of snippets of DNA that were later analysed for signs of loops.

"Our maps of looping have revealed thousands of hidden switches that scientists did not know about before. In the case of genes that can cause cancer or other diseases, knowing where these switches are is vital," said co-author Miriam Huntley, a doctoral student at the Harvard School of Engineering and Applied Sciences.

The research appeared online in the journal Cell.