August 8, 2008

Science Takes Steps Toward Artificial Life

By Robert S. Boyd

WASHINGTON - Scientists are advancing slowly toward one of the most audacious goals humans have ever set for themselves: creating artificial life.

They've already accomplished some steps needed to construct a simple, single-celled organism that's capable of evolving and reproducing itself - basic requirements for life.

"We have made considerable progress," said Jack Szostak, an artificial life investigator at the Howard Hughes Medical Institute in Chevy Chase, Md. "Any prediction like this is just a guess, but I'm hoping we'll have a synthetic cell in under 10 years."

Such a cell would be "unrelated to any existing life form on Earth," Szostak said.

Other experts, however, said it might take decades or centuries before scientists would be able to "create life from scratch," as the quest is colloquially known.

Meanwhile, researchers are laboriously modifying and assembling existing biological molecules to construct synthetic cells with some - but far from all - of the attributes of living creatures.

So far, what they're doing is more like copying nature's clever tricks than creating new life forms in the laboratory, with all the tremendous philosophical, social and religious issues that such a stunning feat would imply.

According to Szostak, a living cell has two essential needs: First, a set of genes that contain instructions for it to eat, grow, divide and reproduce, and second, a surrounding membrane or wall that separates its contents from the outside world but allows nutrients to enter.

In June, Szostak announced his lab had constructed a model "protocell," a synthetic membrane enclosing a copy of an existing strand of genetic material. His team now is trying to synthesize the other half of the puzzle: some form of artificial DNA.

"We've made good progress on the cell membrane, leaving the genetic material as the major challenge," Szostak said.

George Church, a genetics professor at Harvard Medical School in Boston, and Anthony Forster, a pharmacologist at Vanderbilt University in Nashville, Tenn., are the co-authors of a plan to construct what they call a "minimal cell" containing only 151 genes. That's far fewer than the smallest natural microorganism, which has nearly 500.

"Our proposal is quite different from natural life," Forster said. "It will be synthetic life. It will depend on existing parts."

The difficulties don't keep researchers from trying to simulate life, if not create it from a blank slate.

Steen Rasmussen, a physicist at the Los Alamos National Laboratory in New Mexico, heads a "Protocell Project." Its goal is to build lifelike artificial cells that are "self-reproducing and capable of evolution; self-containing, thereby possessing individual identity; self-sustaining in that they can maintain their complex structure."

Hundreds of scientists are working on less ambitious "synthetic biology" projects, aiming to develop useful products to cure diseases, clean up the environment and produce energy.

To speed the process, biological engineers at Harvard and the Massachusetts Institute of Technology in Cambridge have built a library of hundreds of "standard biological parts," which they call BioBricks. The parts are free to researchers at http://www.b

Originally published by McClatchy Newspapers.

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