US researchers have created silkworms that are genetically modified to spin much stronger silk. Writing in the PNAS journal, scientists from the University of Wyoming say that their eventual aim is to produce silk from worms that has the toughness of spider silk. In weight-for-weight terms, spider silk is stronger than steel.

Comic book hero Spider-Man generated spider silk to snare bad guys and swing among the city’s skyscrapers. Researchers have been trying to reproduce such silk for decades.

But it is unfeasible to “farm” spiders for the commercial production of their silk because the arachnids don’t produce enough of it - coupled with their proclivity for eating each other.

Silk worms, however, are easy to farm and produce vast amounts of silk - but the material is fragile. Researchers have tried for years to get the best of both worlds - super-strong silk in industrial quantities - by transplanting genes from spiders into worms. But the resulting genetically modified worms have not produced enough spider silk until now.

GM worms produced by a team led by Professor Don Jarvis of Wyoming University seem to be producing a composite of worm and spider silk in large amounts - which the researchers say is just as tough as spider silk.                            –bbc