Watson's genome, which is being deposited in a public database, is unlikely to remain alone for long. Illumina, a San Diego-based technology company that acquired 454's rival sequencing company, Solexa, earlier this year, plans to sequence the genome of one of the people who contributed DNA to the HapMap project, an effort to catalogue human genetic variation. (See "A New Map for Health.") The National Institutes of Health (NIH) is also planning a personal genome project: it aims to sequence the genomes of 100 different people in the next two years. NIH scientists are currently debating whose genomes would prove most useful to the research community. People included in the HapMap project, which focused on populations in Nigeria, China, Japan, and Utah, are likely candidates. (Craig Venter, a fellow genomic celebrity who pioneered Celera's human genome project, previously revealed that he was the subject of that effort. His DNA now resides in a publicly funded genetic database, and according to the journal Nature, he soon plans to publish a paper describing it.)

454 also aims to create a longer list of personal genomes. Michael Egholm, vice president of molecular biology at 454, predicts that the company will reach the $100,000-genome point within the next year, which he says will be a turning point at which scientists can afford to sequence hundreds of genomes for research purposes. The next step will be the $10,000 genome, which should bring the company within reach of the X Prize Foundation's $10 million award, announced last October, for the first privately funded team that can sequence 100 human genomes in 10 days. (See "The X Prize's New Frontier: Genomics.") "The goal is to make human sequencing routine," says Egholm. "Someday in the future, every human will have their DNA sequenced, probably at birth."

Watson's case also brings back to the forefront many of the ethical issues surrounding the genomic age. Rothberg and others picked Watson as the subject of their first personal genome partly as an homage to a genetic pioneer, but also because, as a geneticist, he is intimately acquainted with the medical and ethical quandaries likely to arise from learning about one's genome and making it publicly available. For example, someone might find out that she has the genetic variant for a largely untreatable or unpreventable disease, such as Alzheimer's. Watson, who has a family history of Alzheimer's, has said that he does not want to know if he carries a specific variation known as APOE4 that's linked to increased risk of the disease.

One of the public's biggest worries about personal genomics is the possibility of genetic discrimination when applying for a job or trying to get health insurance. Various states have legislation preventing this practice, but a corresponding federal bill has been languishing in Congress for years. Peter Traber, Baylor's president, said at the press conference that he hopes the completion of Watson's genome will spur passage of that bill.

Watson said he didn't think too much about the contents of his genome in the interim between giving a DNA sample and getting the results. "I knew I was risking possible anxiety when I saw it," he said. "But it's much more likely that if I don't sleep at night, it's due to thinking about Iraq."