They might not have legs and feet, but single celled organisms need to move around too – and the way they do so looks a lot like walking. Using new imaging techniques, a team of biologists and engineers were able to watch how the amoeba Dictyostelium travels along a surface. Stills from a computer simulation (pictured) show a cell (in grey) travelling from left to right. To move forward, it presses down onto the surface at localised pressure points, shown here by the red areas under the cell. The cell then slides forward, forms a new pressure point and lifts itself off the previous one, much as we use our feet to take a step. This process is also essential to our immune system: neutrophils – white blood cells that ingest microbes and foreign particles – use the same mechanism to patrol the body and travel towards sites of infection.
Written by Emmanuelle Briolat
BPoD stands for Biomedical Picture of the Day. Managed by the MRC London Institute of Medical Sciences the website aims to engage everyone, young and old, in the wonders of biomedicine. Images are kindly provided for inclusion on this website through the generosity of scientists across the globe.