It is not only migratory birds that orient themselves to the magnetic field of the Earth. Also bacteria - supposedly "simple" organisms - have evolved to be able to take advantage of the magnetic field in their search for optimal living conditions. Such "magnetotactic"microorganisms use a miniature, cellular compass made of a chain of single nanomagnets, called magnetosomes. The entire bacterium is oriented like a compass needle inside the magnetic field. Until now, it was not clear how the cells organise magnetosomes into a stable chain, against their physical tendency to collapse by magnetic attraction. But using modern molecular-genetic and imaging processes, researchers from the Max Planck Institue for Marine Microbiology in Bremen and Max Planck Institute of Biochemistry in Martinsried, Germany have identified the protein responsible for creating the magnetosome chain. The scientists showed that this protein aligns the magnetosomes along a cytoskeletal structure which was previously unknown. This points to evidence that genetics regulate the magnetosome chain exactly. The structure is one of the most complex that has ever been found in bacterial cells. It is comparable to organelles that, until now, scientists had only been familiar with in higher organisms. (Nature, Advanced Online Publication, November 20, 2005).