The end of human DNA maps? Little P. Nat Genetics 2001;27:229–230.

Abstract

The February 15 and 16, 2001 issues of Nature and Science, respectively, published maps and sequences of the human genome. This unprecedented accomplishment achieved worldwide attention. The issues of the journals contained the maps/sequences and accompanying articles. The maps/sequences were also published as charts and CDs that accompanied the issues. The Nature consortium was publicly funded in part by the Human Genome Project, and Celera privately funded the Science group. The Nature consortium broke up the DNA in fragments of approximately 150,000 base pairs, using recombinant bacterial artificial chromosomes or phage P1 artificial chromosomes (BACs or PACs, respectively). In essence, the entire human DNA is represented as a series of overlapping 150,000-bp fragments. It is a “map” of overlapping DNAs that is then used by the DNA sequencers who select individual clones (the “clone-by-clone” strategy) for sequencing, with an ultimate goal of filling in the framework of the genome with the DNA sequence. By contrast, the Science group directly analyzed all 3,000 million bases of human DNA, which has been broken up randomly into small fragments of a few thousands of base pairs (the “read” capacity of automated DNA analyzers is not more than 500–1,000 bp). Massive computational efforts were then used to read these short DNA sequences and determine how they overlap. The maps of clones have great usefulness in their own right. The maps/sequences have indicated that any two unrelated individuals differ by about 1 base every 1,000 bases, and the average gene contains 12 variations that are common within populations. Editor’s note: In this issue of the American Journal of Ophthalmology, an abstract of the Nature consortium’s physical map of the human genome is provided along with abstracts of accompanying Nature articles that show how physical maps of various human chromosomes are constructed. Also, an abstract of the Science group’s sequence of the human genome with abstracts of accompanying Science articles interpreting some of the identified genes is included. These maps and sequences of the human genome represent perhaps the most important single scientific accomplishment of this generation.—Hans E. Grossniklaus