Researchers from New York University investigated what happens to the human genome in the absence of the usual gravitational load. To do this, they used a special weightlessness simulator and observed living cells for 24 hours. During this time, the structure and dynamics of the genome remained almost unchanged, and the scientists found no DNA damage.

The results of the study were published in the journal Science Advances.

How scientists created weightlessness on Earth

To study the effect of mechanical load on the cell, the researchers placed living cells in a device that rotates them along a complex three-dimensional trajectory. This motion makes it possible to simulate weightlessness conditions.

For comparison, two more groups of cells were used. One was exposed to a fluid flow that created shear mechanical stress, while the other remained as a control.

After 24 hours, the scientists compared the condition of the cells and their nuclei. Under simulated weightlessness, the nuclear volume increased, but the nuclear envelope retained its normal structure.

The main change turned out to be minor: the organization of the genome itself and the nature of DNA movement inside the nucleus remained almost unchanged. No DNA damage was detected either.

Mechanical impact proved more dangerous than weightlessness

The result of the experiment is especially interesting in comparison with the cells exposed to fluid flow.

In this group, the scientists observed DNA breaks and cell deformation. That is, the mechanical stress arising from fluid movement proved significantly more destructive for the cells than the absence of the usual gravitational load.

“Our data show that the genome, its organization, and dynamics are incredibly resilient and appear not to depend on gravity or its absence after 24 hours of exposure,” said study leader Aleksandra Zidovska.

According to her, the results suggest that the physical organization of the human genome may also be preserved under real spaceflight conditions for a comparable period.

Two meters of DNA inside a nucleus measuring 10 micrometers

The human genome is an extremely compact system. If all the DNA from a single cell were stretched into a line, its length would be about two meters. At the same time, this entire molecule must fit inside a cell nucleus with a diameter of approximately 10 micrometers.

DNA is not simply chaotically folded inside the nucleus. It is organized on several levels, and this spatial structure is connected to gene activity and cell function.

Therefore, any serious changes in genome organization could potentially have health consequences, including increasing the risk of developmental disorders and cancer.

However, the experiment shows only the cells’ response to a relatively short exposure. The scientists emphasize that the absence of noticeable damage after 24 hours does not yet mean that prolonged weightlessness is completely safe.

With longer exposure, small changes may gradually accumulate and later affect cell function. Therefore, the next question for the researchers is what will happen to genome organization if cells remain under microgravity conditions for significantly longer.

This is especially important for future long-duration space missions: judging by the experimental results, the genome tolerates short-term absence of gravity quite well, but the consequences of months or years of exposure still require separate study.