Bionanoscience

DNA in a cell can normally be compared to spaghetti on one’s plate: a large tangle of strands. To be able to divide DNA neatly between the two daughter cells during cell division, the cell organises this tangle into tightly packed chromosomes. A protein complex called condensin has been known to play a key role in this process, but biologists had no idea exactly how this worked. Until February 2018, when scientists from the Kavli Institute at Delft University of Technology, together with colleagues from EMBL Heidelberg, showed in real time how a condensin protein extrudes a loop in the DNA. Now, follow-up research by the same research groups shows that simple bundling up such loops is by no means the only way condensin packs up DNA. The researchers discovered an entirely new loop structure, which they call the 'Z loop'. They publish this new phenomenon in Nature on 4 March, where they show, for the first time, how condensins mutually interact to fold DNA into a zigzag structure.

One of the most fascinating and important properties of living cells is their capacity for self-organization. By talking to each other cells can, among other things, determine where they are in relation to each other and whether they need to turn certain genes on or off. Thus, large groups of cells are able to work together and organise into all kinds of tissues. Researchers at Delft University of Technology have now developed software that can predict and visualise conversations between cells on the basis of the molecules involved.