In human cells, scientists find DNA that looks like a twisted knot instead of a double helix

Biology textbooks may be due for a rewrite.

For the first time, scientists have detected a DNA structure inside living human cells that looks more like a four-stranded knot than the elegant double helix we learned about in school.

The tangled shape, known as an i-motif, had been seen before in the lab, but few researchers expected it to occur in human cells.

The new work shows not only that i-motifs do indeed exist in human cells, but that they may be quite common.

In 1989, Richard N. Goldman (1920-2010) and his wife Rhoda H. Goldman (1924-1996) established the Goldman Environmental Prize, stemming from their lifelong commitment...

"Our imaging suggests that this is a normal thing that happens," said Marcel Dinger, a molecular biologist at the Garvan Institute for Medical Research in Sydney, Australia, who oversaw the research. "It is very likely that genomes in all the cells of our bodies are forming i-motifs at some point in time."

A report on the find was published Monday in Nature Chemistry.

The study lends credence to the idea that...