Alexandra Zidovska
New York University

Editor, Genome Biophysics and Nucleic Acids
Biophysical Journal

What are you currently working on that excites you?

I am very excited by trying to understand physical principles underlying the organization and dynamics of the human genome. The genome is endlessly complex and intricately organized inside the cell nucleus. Really, 2 m of DNA are packed inside a cell nucleus barely 10 µm in diameter, so the cell has to use nifty tricks to do so, and many of them rely on physics. On top of it, it’s not only a packing problem, it also has to be packed in a way that allows easy and fast access to different parts of the genome. Like a gigantic library with easy access to any book you want. At the same time, the genome is dynamic, so this question has literally and figuratively many moving parts.

What has been your most exciting discovery as a biophysicist?

My most exciting discovery has been the discovery of coherent motions of the genome in live cells. Using displacement correlation spectroscopy (DCS), I found that big patches of chromatin—the functional form of DNA in the cell—are moving together for several seconds inside the cell nucleus. This type of motion is present in the cell only when active processes, which use ATP as fuel, are ongoing. Without ATP, it is gone. The coherent chromatin motions are a very interesting phenomenon, as they cause a group of genes to travel together for a short time, and clearly affect the genome organization in the cell nucleus. This is interesting from both a physics and a biology perspective, because it informs our current picture of the genome.