Nature is furnished with malleable building blocks or stem cells, which have the potential to form many different structures, from lung to brain. Damage to stem cell DNA (the structural blueprint) can however affect its potential, so needs to be repaired swiftly. This confocal microscope picture shows DNA repair in action in the nucleus of a mouse embryonic stem cell. Some of its DNA (shown in blue) has been damaged through exposure to ultraviolet light. Within a couple of minutes, repair to the damaged DNA is already underway (indicated by a change in a protein called H2AX, shown in red). Learning more about how stem cells protect themselves from different forms of damage may provide vital clues as to why organs sometimes develop with malformations or defects.
Written by John Ankers
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.