Re: Virus built from scratch in two weeks

[EMAIL PROTECTED] (Baby Peanut) wrote:
>http://www.nature.com/nsu/031110/031110-17.html
>
>Virus built from scratch in two weeks
>New method accelerates prospect of designer microbes.
>14 November 2003
>
>HELEN PEARSON 
>
>Scientists have built a virus from scratch in only two weeks. Their
>new technique paves the way for synthetic viruses and bacteria, but
>stirs concerns over biological weapons and the environment.
>
>The virus was created by genome sequencing pioneer Craig Venter and
>his team at the Institute for Biological Energy Alternatives in
>Rockville, Maryland, and revealed at a press conference yesterday.
>
>It is the second virus to be synthesized from commercially available
>ingredients. The first - a poliovirus completed by Eckard Wimmer and
>his colleagues in 2002 - took three years to make. "If we had to do it
>over, I would use [Venter's] method," says Wimmer, who works at the
>State University of New York at Stony Brook.
>
>Stitch up
>
>Venter's team cobbled together the virus, called phi-X174, following
>its published genetic sequence. They stitched up its DNA from
>ready-made overlapping fragments called oligonucleotides, each built
>from 40 chemical building-blocks, or bases.
>
>The smart part, according to Wimmer, involved steps that eliminated
>genetic errors. For example, the team filtered out common
>oligonucleotides that harbour genetic mutations.
>
>The team used enzymes to glue the oligonucleotides together accurately
>into the complete 5,386-base genetic strand, and to copy it many
>times. When the synthetic viral genome was injected into bacteria, the
>bacterial cell's machinery read the instructions and created fully
>fledged viruses.
>
>Genetically, one of the resulting virus strains was 100% identical to
>the natural virus, says Venter. By contrast, Wimmer's polioviruses,
>which were some 7,500 bases long, had to be laboriously checked for
>mistakes as each genetic piece was added.
>
>Mix and match
>
>The new method is a step towards a bigger goal, claim Venter and
>members of the US Department of Energy, which is funding the work -
>namely, building designer bacteria that can pump out hydrogen fuel or
>gobble up greenhouse gases.
>
>They want to mix and match genes from various organisms to make
>cellular genomes at least 300,000 bases long. The technique will need
>some refining first. For example, a cell might be unable to turn more
>complicated DNA into a working organism without the addition of key
>proteins.
>
>The study may revive concerns that such techniques could one day be
>hijacked to make pathogens such as polio or even smallpox for
>bioweapons. This was widely discussed following the publication of
>Wimmer's work. The prospect of synthetic viruses or bacteria also
>raises fears about their possible environmental impact.
>
>"It reminds us that we'll continue to confront these issues in an
>accelerating way," says public-health expert Stephen Morse of Columbia
>University, New York City. Now, as then, Morse and others argue that
>the benefits of the new technique outweigh the risks and that the
>method should be made public.
>
>The details of the manufacture of virus phi-X174 will be published
>online in the Proceedings of the National Academy of Sciences in three
>weeks1.
>References
>
>   1. Smith, H. O., Hutchison, C. A., Pfannkoch, C. & Venter, J. C.
>Generating a synthetic genome by whole genome assembly: PhiX174
>bacteriophage from synthetic oligonucleotides. Proceedings of the
>National Academy of Sciences, in the press, (2003).
>concatenated
>-----------------------