Breakage in breakage–fusion–bridge cycle: an 80-year-old mystery

2021 marked the 80th anniversary of Barbara McClintock’s pioneering article on the breakage–fusion–bridge (BFB) cycle. Of the three steps of the BFB cycle, breakage remains the least understood despite its major contribution to mutagenesis. We discuss recent findings shedding light on how chromatin bridges break in yeast and animal cells.