Compass-containing bacteria face a challenge when they come to divide: splitting their strong internal magnets. These bacteria use chains of organelles called magnetosomes to orient themselves with Earth's magnetic field, which provides guidance in the water column.

Dirk Schüler of Ludwig-Maximilians University in Munich, Germany, and his team used light and electron microscopy to track the marine bacterium Magnetospirillum gryphiswaldense as it split into two. The dividing cell bends, presumably weakening the strength of the internal magnet to the point that it can be snapped in two. Meanwhile, another mechanism tugs the magnetosome chain towards the centre of the cell so that each daughter cell ends up with its own working magnet.

Mol. Microbiol. 82, 1316–1329 (2011)