This isn’t a horror from the deep, but a developing zebrafish. Its eyes glow red after a trick of genetic engineering. A revolutionary technique called CRISPR/Cas9 allows scientists to edit the fish’s genome – adding or removing genes – providing a useful testing ground for gene editing in other species, including human cells. Here CRISPR inserts an artificial red fluorescent gene that switches on with a natural gene in the lens of the fish’s eye. The new gene produces a red protein in the iris, and also in the fish’s sensory neuromasts – cells dotted around the developing ears that detect vibration in the water, useful when there are predators around. Combined here with a turquoise stain to highlight the developing nervous system, gene-edited zebrafish also have huge potential in exploring genetic disorders and diseases involving similar human genes.
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.