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Celera Genomics plan to build an artificial lifeform
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Thursday, 27 January, 2000, 14:05 GMT
Researchers build huge DNA chains

DNA There are ethical concerns with this type of experiment


Scientists believe they will be able to create synthetic lifeforms within the next decade.

That is the confident prediction of researchers at the University of Texas who have managed to assemble very long strands of the life molecule, DNA, in the laboratory.


The breakthrough that is still necessary to do this is to know how to jumpstart the genome
Professor Glen Evans
Researchers working in this field believe such "engineering" expertise will be an essential first step if we want to make novel bacteria to order. Such microbes could play an invaluable role in medicine, industry and in environmental control.

"Manufacturing" segments of DNA has been a neat trick employed in laboratories since the 1970s. The technique copies the way organisms do it themselves when they duplicate their genetic material prior to cell division.

Enzymes called polymerases will construct a DNA chain from a template given the right conditions and a supply of the four nucleotide bases known as adenine, cytosine, guanine, and thymine - the code of life.

Biological cells

But creating a template and using it to build really long chains, that incorporate useful gene sequences, entirely from scratch, has proved difficult. Now, Professor Glen Evans, at the Southwestern Medical Centre in Dallas, says his team has produced a robotic process capable of joining large chains into very long sequences.


"We've been able to synthesise DNA in the range of 10,000 base pairs," Professor Evans told the BBC. "But we would need to extend that up to about 100,000 to 150,000 base pairs to have the capacity to encode a whole organism."

Just last month, scientists at Celera Genomics, a Maryland biotechnology company, showed that a minimum number of 250 to 350 genes are required to make the most basic living organism. The figure is necessarily vague because the environment in which an organism has to live will influence its biochemistry.

Celera believes there should be an ethical debate before proceeding with any experiment to synthesise an artificial lifeform. The company also says its research on very small microbes has revealed how much we still need to learn about the workings of biological cells before such an experiment could succeed.

Professor Evans, whose research has yet to be published, agrees: "There are still some genes in these organisms that we do not know what they do. We know that they are critical for life, and figuring out what those particular parts are for will be critical for the full strategy to work."

Empty bacterium

But he believes this knowledge will come more quickly than some think and a way will also be found to build the organism. Much speculation has centred on the possibility of building an artificial chromosome to hold the synthesised genome. This might then be placed in the emptied membrane of a microbe.

<I>M. genitalium</I> is the smallest-known bacterium and has become a model for this research M. genitalium is the smallest-known bacterium and has become a model for this research
"This is the critical unknown in this entire effort. The breakthrough that is still necessary to do this is to know how to jumpstart the genome. Even if we can encode the information, we still need somehow to get it started - to do its first round of decoding and synthesising in order to build something that would sustain life on its own."

If scientists can overcome all the obstacles, a huge prize awaits them.

It might be possible, one day, for example, to "infect" a patient with a drug-producing microbe. Once that person has recovered, the microbe could be killed with an antibiotic.

Professor Evans says this could have major advantages over the new therapies scientists are currently struggling to develop.

"So, unlike some of the complicated gene therapy approaches using viruses, inserting one of our proto-organisms would be very safe and it would be very easily removed."





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See also:
10 Dec 99 |  Sci/Tech
Scientists call for life creation debate
10 Dec 99 |  Sci/Tech
Is life just genes?
10 Dec 99 |  Sci/Tech
The mysteries of creation
25 Jan 99 |  Anaheim 99
Creating artificial bugs
03 Dec 99 |  Sci/Tech
Book of life: Chapter one

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