As a three-day-old fruit fly larva starts its transformation into an adult, important changes are going on beneath its skin. This raindrop-shaped structure is the nascent wing, forming from a tiny pocket of cells (stained blue) as they grow in a carefully coordinated fashion. Cells containing a chemical messenger called dpp have been labelled with green fluorescent protein. Dpp helps to control how the wing takes shape, accumulating in a narrow band down the middle to divide its anterior [front] and posterior [back] ends. And it tells nearby cells to ‘switch on’ genes (stained red), which control the development of different parts of the wing. Scientists recently discovered that another protein – called pent – makes sure different parts of the wing grow in proportion with one another.
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.