Staphylococcus bacteria undergo cell division roughly once every 30 minutes. But when the time comes, the actual splitting of one cell into two happens in less than the blink of an eye—about a millisecond, to be precise. The event, known as “popping,” is too swift to be explained by the enzyme-mediated processes thought to govern conventional cell division. Now Julie Theriot and coworkers at Stanford University have made the case that popping is driven not by biochemistry but by mechanics.1
As a Staphylococcus cell prepares to divide, it constructs a double-layered septum that partitions the spherical cell into two hemispheres—the soon-to-be daughter cells. Theriot and her colleagues postulate that as the cell continues to grow, stress builds along the peripheral ring where the septum meets the cell wall until, eventually, the ring cracks. As the crack grows in both directions around the cell’s circumference, the daughter cells tear away...
