Friday, January 25, 2008

Scientist Creates Life — Almost ! He sequenced his own DNA !!!

Scientist Creates Life — Almost

Thursday, Jan. 24, 2008 By ALICE PARK

Not only has Venter constructed the first man-made genome, he has also sequenced his own dna, which is now part of a public genetic database
Venter has devoted much of his career to understanding the engineering of other organisms. He was the leader of one of two teams that in 2000 sequenced the human genome—the entire 25,000-gene cookbook that makes us people in the first place and not chimps or birds or banana trees—and he has conducted the same work with many other organisms. But Venter, 61, may have just done something that is at once more thrilling and promising and unsettling than all that. According to a just-released paper in the journal Science, he has gone beyond merely sequencing a genome and has designed and built one. In other words, he may have created life.

Certainly, defining what we mean when we say life has become a moving target over the years. Are we alive? Yes. Is a virus alive? Maybe. Still, a half-century after the discovery of the double helix, nobody doubts that it is our DNA that determines what we are—in the same way that lines of code determine software or the digital etchings on a CD determine the music you hear. Etch new signals, and you write a new song. That, in genetic terms, is what Venter has done. Working with only the four basic nucleotides that make up all DNA—adenine, cytosine, guanine and thymine—he has assembled an entirely new chromosome for an entirely new one-celled creature. Insert that genome into a cell—like inserting a disc into a computer—and a new species of living thing will be booted up. Venter hasn't done that yet, which is why even he won't say that he has technically invented life. He has, however, already shown that a genome transplanted from an existing cell to another will shut down the host's genetic programming and bring its own online. If that cellular body-snatching works with an ordinary chromosome, there's little reason to think it won't with a manufactured one. "The fact that this is even possible is mind-boggling to most people," Venter says.

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Not only did Venter's team members succeed in building their own mycoplasma at their own lab benches, they also took the opportunity to rewrite its genetic score. First, they introduced a mutation that would prevent it from causing disease. Then they branded it with a series of watermarks that would distinguish it as a product of their lab. Using a code built around selected genes, they spelled out five words that Venter coyly refuses to reveal, saying only that any molecular-biology study can suss them out and promising that there are no obscenities. The next step, which could happen in a matter of months, will be to insert the gene into a cell and see if it indeed stirs to life. "This team is betting its reputation that that will happen in 2008," Venter says.

Not everyone believes he will succeed—or if he does, that it will matter much.

Corporate giants like DuPont already put synthetic biology to industrial use.

In the company's Loudon, Tenn., plant, for example, billions of E. coli bacteria stew inside massive tanks. The bacteria's genomes contain 23 alterations that instruct it to digest sugar from corn and produce propane diol, a polyester used in carpets, clothing and plastics. The hard-working bugs churn out 100 million lbs. (45 million kg) of the stuff each day, and all it took was a little tinkering with their genomes, not the construction of a new one. "In terms of whether I can think of anything I can only do with a whole synthetic chromosome that I can't do now, the short answer is no," says John Pierce, vice president of technology at DuPont Applied BioSciences.

Courtesy: TIME magazine
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