Each dot represents a single cell in the developing embryo, with the number of specialized cells increasing across the 48hrs from embryonic day 6.5 to embryonic day 8.5. The dots are colored based on which major cell type they represent, such as heart, lungs, brain and gut. The 116,000 dots are arranged so that cells with similar genetic activity are close to each other. This new Molecular Map is freely available to researchers to give them access to the complete genetic programs that drive the development of all major organ systems, and opens up new avenues for regenerative medicine and drug development | Credit: Wellcome-MRC Cambridge Stem Cell Institute The eminent biologist Lewis Wolpert famously stated that "It's not birth, marriage or death, but gastrulation that is truly the most important time in your life." Gastrulation represents the process in animal (and human) development whereby precursor cells in the embryo become genetically programmed ...