Humans and other animals store stem cells in special places where they can be activated to regenerate damaged or worn-out tissue. Here, we see one such ‘cell factory’ in the ovary of a fruit fly, with stem cells becoming active (dark patches) and others (stained green) maintained in a dormant state. Keeping them quiet is a complex process and scientists have found a protein called Hh plays a key role. Specialised cells producing Hh grow short ‘fingers’ on their surface to spread it around, so keeping stem cells dormant. But if the protein is unable to do its job - perhaps because of damage or disease somewhere in the factory – the cells respond by extending their soporific fingers up to six times in length to reach into the affected areas. Understanding more about how nature wakes and lulls stem cells will help researchers harness them for medical use.
Written by Mick Warwicker
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.