Polymer physics reveals DNA loops are formed by single molecular motors

Scientists from Skoltech and the University of Potsdam have developed a physical theory that sheds light on how molecular motors organize the three-dimensional structure of the genome. The institutional report frames the development in practical terms and ties it to the broader mission or observing effort.

This matters because physics only takes a result seriously when the measurement chain remains robust under scrutiny. Experimental particle physics and precision metrology both operate in regimes where the signal sits far below the background noise, and where systematic uncertainties can mimic new physics if not controlled rigorously. The history of the field contains numerous anomalies that generated theoretical excitement before better data showed them to be artifacts, and it also contains genuine discoveries that were initially dismissed as noise. The difference is almost always resolved by independent replication with different instruments and different systematics. By Oleg Sherbakov, Skolkovo Institute of Science and Technology This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility: Add as preferred source bioRxiv https: //doi.

BioRxiv https: //doi. org/ Scientists from Skoltech and the University of Potsdam have developed a physical theory that sheds light on how molecular motors organize the. Using theoretical polymer physics and computer simulations, the researchers for the first time calculated a universal parameter of this organization, the density of loops formed.

The findings, published in Proceedings of the National Academy of Sciences, show that 60% to 70% of all DNA in a cell is located within loops, each of which is formed by exactly. This dip arises from the competition between two effects: at very short distances, the signal is blurred due to the finite size of DNA fragments, while at longer distances, loops.

To test the theory, the researchers analyzed more than 30 datasets from human and mouse cells. Student Dmitry Starkov, from the Computational and Data Science and Engineering program, shows that this is not the whole story: the same single cohesin complexes actively.

The broader interest lies as much in the method as in the headline number, because a durable measurement procedure can travel farther than a single result. When experimental physicists develop a technique that achieves new sensitivity or controls a previously uncharacterized systematic, that methodological contribution persists even if the specific measurement is later revised. This is one reason why precision physics experiments often generate long-term value that is not immediately visible in the original publication.

Lifshitz. " Discover the latest in science, tech, and space with over 100, 000 subscribers who rely on Phys. org for daily insights. The authors have released open-source code for extracting loop density from any Hi-C dataset.

Because the account originates with Phys. org Biology, it functions best as a primary institutional report that is close to the data and operations, not as independent scientific validation. Institutional communications are produced by organizations with legitimate interests in presenting their work in a favorable light, which does not make them unreliable but does make them partial. Details that complicate the narrative, including instrument limitations, unexpected failures and results below projections, tend to be minimized relative to progress messages. Technical documentation and peer-reviewed publications, where they exist, provide the complementary layer that institutional releases cannot substitute.

The next step is more measurement, tighter systematic control and scrutiny from groups whose experimental setups are genuinely independent. In experimental particle physics and precision metrology, the threshold for a discovery claim is a five-sigma excess surviving multiple analyses; an intriguing signal at lower significance is a reason to run more experiments, not a reason to revise the textbooks. Next-generation experiments currently under construction or commissioning will revisit several of the open questions that give the current result its context.

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