April 6, 2000
Company Says It Has Finished Map of One Person's Genome
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By CHRISTOPHER S. WREN
he Celera Corporation said today that it has sequenced the human genome, in effect discovering the sequence of DNA molecules in which information on human heredity is inscribed.
Celera, a private company in Rockville, Md., has been racing government-sponsored researchers to decode the human genome, which offers a blueprint to life. The company, which was established barely two years ago, reported that it would now attempt to assemble the genetic fragments in their proper order.
Celera's announcement today drove the stock up nearly 25 percent, to $143 a share, by noon.
Discovering the sequence is an essential step toward mapping the entire human genome, though the real challenge will be to put the sequence together properly. A statement issued by Celera today said that it expected to complete the task over the next few months.
The progress is significant because assembling the full sequence could transform the eventual practice of biology and medicine, providing doctors with a roadmap for confronting diseases at the genetic level and programming the human organism to combat them.
President Clinton announced last month that the United States and Britain had agreed to cooperate by sharing research data to break the codes governing human genetics, and invited private companies to join the effort. But some, like Celera, prefer to proceed alone.
The length of the human genome involves at least three billion bases of DNA, and calculations suggest that the sequence needs to be established a half dozen times to ensure that the assembly is accurate.
The difficulty in comprehending the formula has been that genomes in living creatures contain numerous repeats, which are copies of stretches of DNA that follow nearly identical sequences, confusing the assembly process.
Celera's scientists said earlier this year that they had developed techniques for bridging the repeat stretches to unscramble at least some of them.
The company's research involved establishing the DNA sequence of a single anonymous man. The male gemone is considered scientifically more interesting because it contains both the X and the Y chromosome, while female gemones contain only the X chromosome.
Craig Venter, Celera's chairman and chief scientific officer, told Reuters today, "Now that we have completed the sequencing of one human being's genome, we will turn our computational power to the task of ordering the human genome."
The company next plans to assemble the final human genome sequence from the genes of five anonymous people. This would allow the researchers to compare the donated genes to detect the minute changes that make one human being different from another.
The competing public consortium of researchers subsidized by the government is sequencing a "mosaic" genome in which different segments are taken from about 10 anonymous donors.
Celera, whose operation employs 300 sequencing machines and the largest known civilian computer, last month reported assembling the sequencing of the genome of a fruit fly.
Writing in the magazine Science, two researchers, Eugene W. Myers and Edward Winstead, explained that the assembly began with 3.1 million fragments of the genome, which they desribed as "random bits of fly DNA that have been converted into characters that a computer can read." The fragments, they said, provided enough DNA to cover the genome 14 times over.
The task, they said, had been "to arrange these DNA sequences into a properly ordered and nearly complete genome," by matching the overlapping sequences.
