sptlt217Survival depends on cues, mobility and a medium to evolve in. Cues - such as scents, sounds or colours for example - will attract organisms towards food, mating grounds and an environment in which they feel protected and are happy to stay. Thanks to them, organisms usually head off in a direction they expect will be to their advantage, using the means of locomotion they have, to cross all sorts of media. A few organisms use yet additional systems to reach a given destination. An example? Magnetotactic bacteria have learned to use the Earth's magnetic field as a speedy highway to travel to nutrients of interest. They do this by way of minute iron-rich pouches - or magnetosomes - that are aligned along their middle and act much like a compass would. Many macromolecules are required to model this fascinating system. One of particular interest is a protein known as MamB which is at the heart of magnetosome initiation. Magnetosomes have also long intrigued those behind the microbiology blog Small Things Considered, and this article echoes a lovely piece on magnetotactic bacteria and their navigation skills written by Christoph Weigel earlier this week, and whose artwork is shown below. Read more