Goats to Produce Spider Silk

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Goats to Produce Spider Silkwritten by Maria Godoy, Tech Live

http://www.g4tv.com/techtvvault/features/35552/Goats_to_Produce_Spider_Silk.html

 

Using gene splicing, genetic engineering firm reproduces nature's toughest fiber.

 

 

What do you get when you cross a goat with a spider? A Canadian biotech firm has used gene splicing to find out. The result, says Quebec-based Nexia Biotechnologies, is a synthetic version of spider silk that's biodegradable but also strong enough to stop bullets. Spider silk has long been admired for its amazing strength. The toughest kind is called dragline silk: It forms the framework of the spider web, and it's also what the spider spins when it jumps. "Dragline silk is known as having greater tensile strength than steel, which is incredibly strong, given the diameter of the actual thread," said Rosemary Gillespie, a spider expert with the University of California at Berkeley. To create a synthetic version of nature's wonder fiber, the Nexia scientists took the silk genes from a spider and spliced them together with cells taken from cows and hamsters. The result was a thick fluid of proteins that, when exposed to air, self-assemble to form filaments just like natural spider silk does. "We have been able to take 400 million years of evolution and reproduce it in the lab," said Costas Karatzas, vice president of research and development at Nexia. "What we've been able to do is produce the material in the lab artificially, use water-based solutions to spin out threads of continuous fibers that have mechanical properties that mimic the properties of the native spider silk." Past attempts to take advantage of spider silk's properties have met several stumbling blocks. Farming spiders proved out of the question, illespie says. Their belligerent nature makes it impossible to farm spiders in the manner of silk worms. "You can't have millions of spiders living together in a confined space. They eat each other," she said. Until now, attempts to recreate spider silk in the lab had met with limited success. While other researchers have also been able to reproduce spider proteins, they had been unsuccessful in turning those proteins into usable fibers as strong as natural spider silk, Gillespie said. Nexia now plans to harvest the silk proteins from the milk of goats it has genetically engineered with the spider genes. The goats are expected to start producing milk in the spring. Once that happens, the milk will be purified so only silk proteins and water remain, allowing the synthetic spider silk to self-assemble. Nexia says its BioSteel fiber will likely see its first use as medical sutures, although the company sees the material eventually being used in everything from bullet-proof body armor to fishing lines.