Like jewels in a vault, our precious genetic material is stored in the nucleus of a cell–sequestered away from potentially damaging cellular components and toxins so that no harm can come to it. Yet over the course of a life moving through this world, our DNA does get damaged, and our cells have a host of complicated repair mechanisms to deal with such injuries.
In this cross section of a kidney from a young FAN1 knockout mouse, cell nuclei are stained purple. Cells within a structure called the renal tubule exhibit karyomegaly, or enlarged nuclei.
Credit: The Laboratory of Genome Maintenance of The Rockefeller University/Genes and Development