Playing God?
Manmade DNA powers cell
The image provided by the J. Craig Venter Institute shows negatively stained transmission
Scientists announced a bold step in the enduring quest to create artificial life. They've produced a living cell powered by manmade DNA. While such work can evoke images of Frankenstein-like scientific tinkering, it also is exciting hopes that it could eventually lead to new fuels, better ways to clean polluted water, faster vaccine production and more. Is it really an artificial life form? The inventors call it the world's first synthetic cell, although this initial step is more a re-creation of existing life changing one simple type of bacterium into another than a built-from-scratch kind. But Maryland genome-mapping pioneer J. Craig Venter said his team's project paves the way for the ultimate, much harder goal: designing organisms that work differently from the way nature intended for a wide range of uses. Already he's working with ExxonMobil in hopes of turning algae into fuel. "This is the first self-replicating species we've had on the planet whose parent is a computer," Venter told reporters. "It's been a long time coming, and it was worth the wait," said Dr. George Church, a Harvard Medical School genetics professor. "It's a milestone that has potential practical applications." Following the announcement, President Barack Obama directed the Presidential Commission for the Study of Bioethical Issues he established last fall to make its first order of business a study of the milestone. Scientists for years have moved single genes and even large chunks of DNA from one species to another. At his J. Craig Venter Institute in Rockville, Md., and San Diego, Venter's team aimed to go further. A few years ago, the researchers transplanted an entire natural genome the genetic code of one bacterium into another and watched it take over, turning a goat germ into a cattle germ. Next, the researchers built from scratch another, smaller bacterium's genome, using off-the-shelf laboratory-made DNA fragments. The report combines those two achievements to test a big question: Could synthetic DNA really take over and drive a living cell? Somehow, it did. "This is transforming life totally from one species into another by changing the software," said Venter, using a computer analogy to explain the DNA's role. The researchers picked two species of a simple germ named Mycoplasma. First, they chemically synthesized the genome of M. mycoides, that goat germ, which with 1.1 million "letters" of DNA was twice as large as the germ genome they'd previously built. Then they transplanted it into a living cell from a different Mycoplasma species, albeit a fairly close cousin. At first, nothing happened. The team scrambled to find out why, creating a genetic version of a computer proofreading program to spell-check the DNA fragments they'd pieced together. They found that a typo in the genetic code was rendering the manmade DNA inactive, delaying the project three months to find and restore that bit. "It shows you how accurate it has to be, one letter out of a million," Venter said.
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