DNA repair is deleterious during mitotic phase
Cells have mechanisms to repair broken DNA molecules. The machinery to repair broken DNA, specifically, double stranded breaks (DSB), is shut down when the cells are dividing, i.e. when cells are in mitotic phase.
In a recently published paper by researchers from The Lunenfeld-Tanenbaum Research Institute and University of Toronto observed the effects of restoring the DSB repair machinery in mitotic cells. They found that restoration of this machinery was actually harmful and caused the ends of the chromosomes to fuse. This resulted in dicentric chromosomes and aneuploidy.
In a recently published paper by researchers from The Lunenfeld-Tanenbaum Research Institute and University of Toronto observed the effects of restoring the DSB repair machinery in mitotic cells. They found that restoration of this machinery was actually harmful and caused the ends of the chromosomes to fuse. This resulted in dicentric chromosomes and aneuploidy.