When he was president of Celera Genomics, Craig Venter was the leader of the private project which deciphered the human genome -- ahead of the public Human Genome Project.
Now, he has another goal: create custom-made organisms -- one DNA letter at a time. Alexandra M. Goho gives us detailed explanations in this long article. Here are some excerpts.
Venter’s objective is not merely to tweak existing life forms by inserting genes that confer specific traits -- the main tactic in conventional genetic engineering. Instead he wants to assemble an entire genome, DNA letter by DNA letter, putting together only the genes he wants: those necessary for an organism’s survival and those that will allow it to carry out a desired task.
"The long-term advantage of creating an organism from a chemically synthesized genome is that it allows complete flexibility of design," says University of North Carolina biologist Clyde Hutchison. No longer limited to nature’s repertoire, researchers could create a wide variety of synthetic organisms, each made to perform a specific chore, such as sopping up oil slicks or producing a plastic.
Goho traces the roots of Venter's goal to an earlier effort, the Minimal Genome Project.
The team started with a lowly bacterium called Mycoplasma genitalium, whose tiny genome consists of just 517 genes made up of about 580,000 DNA letters. "I raised the question: Does the bacterium need all those genes?" says Hutchison, who had taken a sabbatical from the University of North Carolina to work on the project. By selectively disabling different genes, the researchers discovered that only 265 to 350 were essential: few enough to make it conceivable that researchers could assemble the entire genome from scratch, though the endeavor might take a decade or more.
Then Goho looks at some similar efforts under development, in particular at State University of New York at Stony Brook, at Egea Biosciences, a private company from San Diego, or at the the Scripps Research Institute in La Jolla.
"We’ve removed a billion-year-old constraint on what we can do with proteins," says a Scripps chemist, Peter Schultz. "And so we’re taking the point of view that if God had worked on Sunday, and he had more amino acids to work with, what would have been the outcome?" Would an organism with an expanded genetic code and amino acid inventory have an evolutionary advantage?
If scientists could answer such big theoretical questions, says Stephen Freeland, an evolutionary geneticist at the University of Maryland, it might be possible one day to discover on other planets life that might not otherwise be recognizable. And if the synthetic-genome technologies in the works at Scripps, Egea, Venter’s institute, and elsewhere pan out, life right here on Earth could soon look a little less familiar -- and a lot more diverse.
I urge you to read the whole eye-opening article for many more insights.
Source: Alexandra M. Goho, Technology Review, March 24, 2003
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