Abstract

In a report issued in January 1988, the National Research Council (NRC) Committee on the Mapping and Sequencing of the Human Genome, on which the present authors served, recommended a staged mapping and sequencing project with early emphases on physical mapping of human DNA, mapping and sequencing of the genomes of model organisms, and the development of sequencing technology (1). As the Committee's recommendations on physical mapping are beginning to be implemented on a substantial scale, it is timely to review these recommendations in the light of recent technical advances. In particular, the polymerase chain reaction (PCR) (2), a method that has only come into widespread use during the past 2 years, seems to us to offer a path toward a physical map that largely circumvents two problems that were prominent in the NRC Committee's discussions. One of these was the difficulty of merging mapping data gathered by diverse methods in different laboratories into a consensus physical map. The second was the logistics and expense of managing the huge collections of cloned segments on which the mapping data would depend almost absolutely.