Scientists create 'spider-goat'

Scientists have made an astonishing breakthrough by successfully crossing a spider with a goat to produce silk that is tougher than steel.

The new fibre is designed to create a bullet-proof vest for the US Army that can stop a shot from any gun.

The spider-goat is believed to be the first commercially viable animal created from the DNA of two species - and could be worth millions for the Canadian company behind the research.

It also marks a significant shift in the debate about genetic experiments. Dolly the sheep was created by British scientists researching human health. Now similar technology is being used to create tools for the military.

Outward ly, the animals resemble ordinary goats. But at a transgenic farm run by Nexia Biotechnologies in rural Quebec they are being bred with a single gene from a golden orb-weaving spider.

Milk from the female goats contains silk that is five times the strength of steel. It is being used by the Pentagon to develop body armour that would be four times stronger than Kevlar but weigh less than a cotton shirt.

Other commercial possibilities include using it to make biodegradable fishing lines and surgical stitches.

The product - dubbed BioSteel by Nexia - could also grab a huge slice of the £1 billion market in industrial fibres. It could be woven to produce couture clothing that would feel almost weightless, scientists claim.

Hybrid spider-goats are bred using test-tube techniques. A single gene from the common orb-weaver or garden spider is inserted into fertilised goat eggs. Each baby goat is only 1/70,000th spider but when fully grown the females are able to produce a milk that contains a protein identical to spider silk.

In experiments, Nexia researchers have been able to produce 91 metres of BioSteel an hour.

Scientist have long known that spider silk is one of the strongest substances in the world but have been unable to reproduce it artificially. Attempts to farm spider silk have also failed, because spiders are highly territorial and attack and kill each other if kept in captivity.

The Pentagon experiment is being conducted on a former nuclear missile base north of New York. A herd of 302 goats will gradually grow to 1,500 in the coming months. Researchers have found the animals are happiest listening to the music of Dolly Parton.

Dr Jeffrey Turner, the president and chief executive of Nexia and the head of the scientific team, calls the silk breakthrough "the holy grail of material science".

He said: "Spider silk is a material science wonder, a selfassembling, biodegradable, nanofibre structure one-tenth the width of a human hair that can stop a bee travelling at 20mph without breaking. Spider silk has dwarfed man's achievements in material science to date.

"Man always thinks strong things have to be big but the spider has dwarfed what we've done with petroleum-based materials."

Nexia licensed the blueprint for extracting spider genes from the University of Wyoming three years ago but has only recently been able to create enough spidergoats to make the silk in industrial quantities.

Earlier attempts to produce socalled "transgenic species" have included a cancer-prone mouse developed at Harvard University for medical research and a monkey born last year with the DNA of a jellyfish that glowed in the dark.

But other medical and scientific experts have warned against creating new species. Dr Andre Menache, the head of Doctors and Lawyers for Responsibl e Medicine, based in London, has called such experiments "a perversion of science".

Concern about genetically modified animals and plants is not as widespread in the US. The Bush administration is deciding whether to approve a "supersalmon" for human consumption, although some states are considering laws to curtail the use of transgenic animals.