It may not look like much, but the green blob on the right has travelled further than most of us ever will. It's the thymus from a mouse that went on the final flight of the Space Shuttle Atlantis – the historic last mission for the US shuttle programme. Based on studies of mice on previous flights, researchers suspected that space travel might affect the thymus, an important part of the immune system, but it's not possible to take body parts out of astronauts to look in detail at them. The scientists discovered higher levels of broken DNA in the mouse's thymus after a 13-day trip on the shuttle, highlighted by a green stain that detects DNA damage, compared to the thymus of an earth-bound counterpart (left-hand panel). This damage could affect the immune system and needs to be taken into account as we start to explore the universe.
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.