The scientists captured the highest resolution images ever obtained of DNA, revealing unprecedented twisting and twisting behaviours.
According to new research published in Nature Communications, deoxyribonucleic acid, also known as DNA, can be surprisingly active when heaped and twisted inside a cell.
These hidden movements were revealed by computer simulations fed with the highest resolution images ever obtained of a single DNA molecule. The new study exposes behaviours never seen before in the self-replicating molecule, and that research could lead to the development of powerful new genetic therapies.
“Seeing the helical structure of the entire DNA molecule was extremely challenging,” said Alice Pyne, the first author of the article and materials scientist at the University of Sheffield, in a university statement. “The videos we have developed allow us to observe the twisting of DNA with a level of detail never seen before.”
Scientists have used microscopes to observe it and its twisted-ladder configuration, but these were limited to static visualizations of the molecule. What scientists failed to see is how the intense folding of DNA affects its double helix structure. To do this, Pyne and his colleagues combined high-resolution atomic force microscopy (AFM) with computer simulations of molecular dynamics, which revealed the contortions.
Long, highly organized strands are squeezed into our cells. As the new study shows, this results in some surprisingly dynamic physical behaviours.
Agnes Noy, a professor at York University and co-author of the study, said the microscopic images and computer simulations combined so well that they increased the resolution of their experiments, allowing the team to “track how each atom in the DNA double helix dances. “
For the study, the researchers analyzed minicircles of DNA, in which a small strip is joined at both ends, forming a loop structure. DNA minicircles have been described before and are considered essential health indicators.
Microscopic images of minicircles of DNA in their “relaxed” position (i.e., without twists) revealed tiny movement, but extra twists brought the loop to life, resulting in more vigorous activities. These dynamic movements can serve an essential purpose, helping DNA to find liaison partners and facilitate growth.
The new atomic force microscopy shows, “in remarkable detail”, how “wrinkled, blistered, twisted, denatured and strangely” the minicircles really are, “and which we hope to be able to control someday”, he said. Baylor College of Medicine biologist Lynn Zechiedrich, who provided the minicircles for the study, in the statement from the University of Sheffield.
According to the researchers, more insights into it and how it can become so compact could lead to the development of entirely new medical interventions, including improved DNA-based diagnostics and therapies.