Misreplication of DNA in human fibroblast nucleus

Super-resolution optical micrograph of DNA stain in a human foetal lung fibroblast nucleus acquired with a 3D structured illumination microscope (3D SIM). A rare phenomenon has occurred in this image; the majority of the genome has been caught in misreplication. If a single chromosome becomes caught and pulled between the two new cells, it can lead to the presence of small chromatin threads/bridges joining adjacent nuclei. This leads to clearly demarcated chromatin fibres visible throughout the interior of the nucleus, and as the new cells move apart the tension distributed by the cable-like chromatin has deformed the entire nuclear envelope. The width of the image is 84 micrometers.