Friday, August 12, 2011

Artificial Lifeform Developed in US

Scientists in the US have succeeded in developing the first living cell to be controlled entirely by synthetic DNA. The researchers constructed a bacterium's "genetic software" and transplanted it into a host cell. The resulting microbe then looked and behaved like the species "dictated" by the synthetic DNA.

 The advance, published in Science, has been hailed as a scientific landmark, but critics say there are dangers posed by synthetic organisms.  Some also suggest that the potential benefits of the technology have been over-stated.  But the researchers hope eventually to design bacterial cells that will produce medicines and fuels and even absorb greenhouse gases.

The team was led by Dr Craig Venter of the J Craig Venter Institute (JCVI) in Maryland and California. He and his colleagues had previously made a synthetic bacterial genome, and transplanted the genome of one bacterium into another.  Now, the scientists have put both methods together, to create what they call a "synthetic cell", although only its genome is truly synthetic. Dr Venter likened the advance to making new software for the cell.

The researchers copied an existing bacterial genome. They sequenced its genetic code and then used "synthesis machines" to chemically construct a copy. The scientists "decoded" the chromosome of an existing bacterial cell - using a computer to read each of the letters of genetic code.  They copied this code and chemically constructed a new synthetic chromosome, piecing together blocks of DNA. The team inserted this chromosome into a bacterial cell which replicated itself. The new bacteria replicated over a billion times, producing copies that contained and were controlled by the constructed, synthetic DNA.

"As soon as this new software goes into the cell, the cell reads [it] and converts into the species specified in that genetic code. This is the first time any synthetic DNA has been in complete control of a cell," said Dr Venter. Dr Venter and his colleagues hope eventually to design and build new bacteria that will perform useful functions.  "I think they're going to potentially create a new industrial revolution," he said. "If we can really get cells to do the production that we want, they could help wean us off oil and reverse some of the damage to the environment by capturing carbon dioxide."  Dr Venter and his colleagues are already collaborating with pharmaceutical and fuel companies to design and develop chromosomes for bacteria that would produce useful fuels and new vaccines.

The ethical discussions surrounding the creation of synthetic or artificial life are heating up. Dr Helen Wallace from Genewatch UK, an organization that monitors developments in genetic technologies, said that synthetic bacteria could be dangerous. "If you release new organisms into the environment, you can do more harm than good," she said. "By releasing them into areas of pollution, [with the aim of cleaning it up], you're actually releasing a new kind of pollution. "We don't know how these organisms will behave in the environment."
 Dr Venter said that he was "driving the discussions" about the regulations governing this relatively new scientific field and about the ethical implications of the work.  Professor Julian Savulescu, from the Oxford Uehiro Centre for Practical Ethics at the University of Oxford, said the potential of this science was "in the far future, but real and significant".  But the risks are also unparalleled," he continued. "We need new standards of safety evaluation for this kind of radical research and protections from military or terrorist misuse and abuse. These could be used in the future to make the most powerful bioweapons imaginable. The challenge is to eat the fruit without the worm."

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