| Fate Maps |
What Sulston and his colleagues did with tracing the entire cell lineage would be exceedingly difficult for the vast majority of organisms. Most multicellular organisms have far more cells than C. elegans. Moreover, most don't have a transparent body or rather sedentary cells during development. Nevertheless, for several different kinds of organisms, researchers have been able to determine the type of tissue that cells in developing embryos will become; fate maps are diagrammatic representations of this (Fig. 7).
Scientists have been able to create fate maps for several organisms (such as the sea urchin) since the early decades of the twentieth century. To construct fate maps researchers use various methods, including removing cells from embryos. If the adult that developed from these embryos is missing specific tissues, researchers infer that the removed cells would have become those missing tissues. Researchers can also use a variety of stains to trace cells in the developing embryo.