One of the greatest mysteries in biology is how living things grow from a single fertilised egg cell into a complex organism. And the biggest challenge facing researchers trying to answer this question is how to spy on individual cells as they grow, multiply and specialise. Help is at hand from a clever genetic engineering system called Brainbow. It makes individual cells in a developing organism switch on unique combinations of red, blue and green fluorescent molecules, 'painting' each one a distinct colour. Scientists have now adapted this system to work in zebrafish, naming it Zebrabow. This striking picture shows the fin on the side of an adult Zebrabow fish – the clusters of cells that are all the same colour grew from the same cell in the embryo. The technique could prove powerful for enabling scientists to track the origins of different tissues, revealing how they form and grow.
Written by Kat Arney
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.