NYU Study Finds Human Genome Stays Robust Under Simulated Microgravity

The human genome's physical organization appears largely unaffected by a day of simulated microgravity, according to a new study led by researchers at New York University's Center for Soft Matter Research. The findings, which isolate gravity's influence on human cells, offer early reassurance for the biology of long-duration spaceflight while pointing to risks that may emerge over longer exposures.

The research set out to answer a question that remains open despite the completion of the Human Genome Project in April 2003: what physical rules govern how the genome organizes itself, and what role gravity plays. Decades of expeditions to the International Space Station have shown that prolonged time in space can cause muscle atrophy, bone density loss, vision problems, and effects on the cardiovascular and central nervous systems. NASA's Twins Study, comparing astronaut Scott Kelly after a year in space with his Earth-bound brother Mark, revealed that microgravity affects astronauts at the genetic level, though the full extent is not yet known.

To study gravity's effect directly, the NYU team designed and built a Random Positioning Machine similar to those used in astronaut training. The machine rotated dishes of living cell cultures along two axes following a three-dimensional path, allowing the team to image genes and observe how they responded to microgravity. The researchers also developed 3D algorithms to simulate microgravity while minimizing fluid flow, a byproduct of Earth-based rotation experiments that is absent in true microgravity. Those innovations reduced both flows and the formation of cell aggregates, which had obscured microgravity effects in earlier studies.

After 24 hours of exposure to simulated microgravity or fluid flows, the scientists used advanced imaging to record streams of images and analyze changes in the cells, their nuclei, genome organization, dynamics, and possible DNA damage. The results showed that microgravity increases the volume of the cell nucleus, indicating that gravity diminishes it, while exposure to flows elongated the cells. The thickness and structure of the nuclear envelope remained unchanged, suggesting gravity has minimal impact on those traits. The genome inside the nucleus maintained its physical organization and motions. Microgravity did not cause DNA damage, but damage did occur when cells were exposed to flows.

Alexandra Zidovska, an associate professor in NYU's Department of Physics, framed the stakes of the work. "On Earth, the role of gravity is intriguing, it is a constant mechanical stress on everything," she said, explaining that removing gravity as a force was necessary to uncover its role. "Our data show that the genome, its organization, and dynamics are incredibly robust and seem unaffected by gravity, or lack thereof, after 24 hours." She added that the physical organization of the human genome may change little in space over comparable timeframes, though changes could occur during longer exposures and from DNA damage occurring in space.

The team described the day-long changes as subtle but noted they could amplify over time. The study offers fundamental insights into genome organization and highlights gravity's role in regulating life on Earth, with results suggesting the genome could withstand microgravity without serious changes over short periods.

The researchers stress that this experiment is only an early step in understanding the long-term effects of microgravity. Mapping the full range of effects is described as essential for future long-duration missions to the Moon, Mars, and beyond. The paper was published in Science Advances.