Scientists Discover Chromosome Fluidity

Outside of their replication and division phases, chromosomes were found to be pliable, if not liquid.

The ability to move chromosomes around inside living cells proves they are malleable.

Scientists from the French National Center for Scientific Research (CNRS), the Curie Institute, and the Sorbonne University have successfully performed the first direct physical manipulation of chromosomes in living cells. When they subjected chromosomes to varying stresses using magnets, they discovered that, outside of cell division phases, chromosomes are remarkably malleable, nearly liquid. This research was just released in the highly-regarded journal Science.

Chromosomes are pliable, albeit not liquid, substances when not undergoing cell division. The first time that chromosomes in a living cell's nucleus have been directly mechanically manipulated has allowed for this breakthrough finding.

Chromosomes, extremely long DNA molecules, were formerly depicted as tangled like loose balls of yarn, producing a gel-like substance. The findings of this new publication paint an entirely different image. A cell's chromosomes are mobile and can rearrange themselves without interference from the other components of the nucleus.

Scientists from the Nuclear Dynamics, Physical Chemistry and Cell Biology, and Cancer laboratories at CNRS, the Curie Institute, and Sorbonne University, in collaboration with scientists from the Massachusetts Institute of Technology, attached magnetic nanoparticles to a small portion of a chromosome in a living cell and published their findings in Science. The chromosome was then stretched using an external micro-magnet to apply varying tension. By taking this method, the groups could quantitatively evaluate how a chromosome reacts to external pressures for the first time in a living cell.

These studies demonstrated that the range of stresses exerted naturally in the nucleus, such as by enzymes copying DNA, is sufficient to alter a chromosome's conformation significantly. Located at the crossroads of physics and biology, this groundbreaking finding modifies the standard depiction of chromosomes. It also enriches our knowledge of biological mechanisms, chromosome biophysics, and genome structure.