Chromosomes need to be properly aligned before they can be pulled apart. Each panel in this picture shows how DNA (stained purple) within chromosomes tries to align in the centre of a cell ready for division. Over time, (time flows from top to bottom) the chromosomes in the left panel are tugged back and forth around a spindle [structure that helps anchor chromosomes] by a protein called dynein (shown in white). Eventually this oscillation slows down and the DNA lines up in the right place. Scientists changed spindle oscillations by either blocking the activity of dynein (second panel) or adding a drug to hamper spindle activity (third and fourth panels). Understanding how to stop cells from dividing paves the way for halting the growth of tumours.
Written by John Ankers
BPoD stands for Biomedical Picture of the Day. Managed by the MRC London Institute of Medical Sciences (the new name for the MRC Clinical Sciences Centre) 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.