Animals develop according to a programed pattern – they follow one line from head to tail, and another from back to belly. In fruit fly embryos this pattern of development is orchestrated by a protein called dorsal, which switches certain genes on and off. Dorsal levels are spread unevenly around the embryo’s girth. The amount determines which genes are expressed where, which in turn dictates the fate of new cells. This embryo cross section shows the system at work. Each colour represents a different gene. At the top, where there is least dorsal protein, a gene called dpp (stained yellow) is turned on. At the bottom, high concentrations of dorsal switch on another gene (red). So this fluorescent pinwheel helps scientists understand how the right sorts of cells end up in the right place.
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BPoD stands for Biomedical Picture of the Day. Managed by the MRC Laboratory of Medical Sciences until Jul 2023, it is now run independently by a dedicated team of scientists and writers. The website aims to engage everyone, young and old, in the wonders of biology, and its influence on medicine. The ever-growing archive of more than 4000 research images documents over a decade of progress. Explore the collection and see what you discover. Images are kindly provided for inclusion on this website through the generosity of scientists across the globe.
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