Our blood vessels are built along tubes of epithelial cells. Specific proteins inside these cells control the growth of the tube as it extends. Air pipes of the fruit fly, Drosophila, grow in a very similar manner to human blood vessels. Here we see epithelial cells expressing differently-coloured fluorescent proteins in the airways of two different flies. The top image shows epithelial cells spreading evenly from left to right along the air pipe (white line). But in a fly lacking a protein called Src42A (bottom image) cells are stretching away from the tube and bunching together. As similar proteins are at work in both Drosophila and human organs, fly studies often provide vital clues to aid drug design, in this case to prevent the malformation of blood vessels in conditions like polycystic kidney disease.
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.