The image on the left shows a pair of lungs from a mouse foetus, a couple of days before birth. If you look carefully you can see the network of delicate branching tubes that draw in air, sending it down to tiny sacs called alveoli. It’s here where vital oxygen moves into the bloodstream and waste carbon dioxide passes back out. But there's something very wrong with the lungs on the right, taken from an animal at the same age. The regular branches have failed to sprout, thanks to a fault in a gene called Ext1, so these mice can’t breathe properly after they’re born. Ext1 works together with a well-known gene called Sonic hedgehog, which sends signals in developing organs that help them grow into the correct structures. The discovery reveals more about how lungs grow, and what has gone wrong when human babies’ lungs don’t develop properly.
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.