How our organs sense the expansion of other tissues and alter their size, coordinating their growth, remains quite a puzzle. To find out more, scientists turn to fruit flies, which unlike mammals grow quickly and are readily modified genetically. A molecule called Dilp8 was known to be key in ensuring that organs grow in relation to body size, and can affect when metamorphosis happens. But how does it know when to act? Looking at different proteins using fluorescent tags in a fruit fly embryo (pictured), the team found that nerve cells bearing a protein called Lgr3 were in certain locations in the central nervous system (arrowed). They discovered that it’s these cells that ‘sense’ Dilp 8 activity, moderating growth and developmental timing by interrupting it as necessary, leading to a normally developed fly. Understanding the molecular signals that coordinate growth in flies is providing vital insight into our own development.
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.
BPoD is also available in Catalan at www.bpod.cat with translations by the University of Valencia.