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.
Read the rest at Nature nature.com031110 17.htmlOpen ↗
Breast-feeding promotes wound healing Rat study may fuel breast-versus-bottle debate. 12 November
2003 HELEN R. PILCHER
Breast-feeding may help the scars of childbirth fade. Lactation speeds wound healing and lowers
stress in rats, researchers told this week's Society for Neuroscience Annual meeting in New Orleans,
Louisiana.
"It's quite possible that mothers who breast-feed their newborns will have accelerated healing of
tissue damage compared with mothers who bottle-feed," says Tara Craft from Ohio State University in
Columbus, who studied the rats.
The results could fuel the breast-versus-bottle debate. Breast-is-best advocates claim that breast-
fed babies have fewer allergies, infections and stomach upsets. Maternal health benefits are often
overlooked, however. Natural and caesarean births can leave substantial wounds, says Craft, who now
plans to study wound healing in human mothers.
Craft's team gave rats small skin wounds the day after they littered. Five days later, their
injuries were 30% smaller than those of animals prevented from breast-feeding.
nature.com031110 11.htmlOpen ↗
Comment: Every first aid kit should include a lactating rat?
Kind Regards, Robert Karl Stonjek.