Much of the machinery in cells is devoted to division, but in the earliest cells this process may have been governed by changes in the ratio of surface area to volume.

Although all bacteria either have cell walls or are thought to have evolved from ancestors that did, Jeff Errington and his colleagues at Newcastle University, UK, found that excess production of cell membrane in mutants of the bacterium Bacillus subtilis drives them into a state without cell walls. Non-mutant bacteria forced into a shape with a greater surface-to-volume ratio also lost their cell walls. In both cases, cells divided through irregular bulges, rather than dedicated cell-division machinery.

In addition to providing a model for early cells, this work could help to explain how some infectious bacteria resist antibiotics.

Cell 152, 997–1007 (2013)