Mapping the worm’s genome
Since the 1960s, when Sydney Brenner introduced the small free-living nematode Caenorhabditis elegans as new model organism for the study of development, the worm has been the object of extensive mapping projects. Linkage maps of its genes were followed by cell lineage maps, by detailed maps of its nervous system and by a complete physical map of its genome. In 1998, the complete sequence of its genome was announced. It was the first multicellular organism of which the full sequence was known. In connection with the other maps, the sequence, freely available to researchers on the web, established C. elegans as a key organism for biological research. The worm-sequencing project further served as a pilot for the human genome project. The success story of C. elegans, recognized by last year’s Nobel award to Sydney Brenner and two of his early collaborators on the project, John Sulston and Bob Horvitz, testifies to the key role of maps in current biological practice. This point continues to be obscured by the fact that mapping is often perceived as a service function or lower status activity, the recent euphoria surrounding the sequencing of the human genome notwithstanding (de Chadarevian 2000; Ankeny 2001). At the same time, the close succession of the worm-mapping efforts, which often involved the same people, invites comparison of the different projects. Are they all part of the same ‘mapping culture’ or can we discern differences? And how do the different maps relate to each other?