Imagine milking goats not to take white butter or fromage de chèvre to the farmers’ market, but to sell spider silk proteins.
The concept was originally brought to the lab by Montreal scientists in 1999, who cloned identical triplet goats in the hopes of eventually producing transgenic goats that could be milked for spider silk, or “BioSteel.” Though fruitful in their efforts, the group failed to bring the product to market, resulting in the bankruptcy and dismantling of their company in 2009.
Enter Randy Lewis.
Lewis was a contributor to the Canadian-based project, having cloned and licensed the proteins used by the company. He had long worked with spider silk, publishing numerous articles on its structure. And though he understood the potential behind the material, he seemed to accept that spider farms were not likely to gain much momentum.
“Scientists have known since the late 1800s that farming spiders isn’t possible—spiders tend to eat other spiders within the vicinity,” said Lewis, now a professor at Utah State University’s College of Science, and one of the leaders in keeping spider silk producing goats in North America's web of research.
Besides their cannibalistic nature, spiders also produce six different kinds of silk, making the desired silk -- often dragline silk -- rather difficult to harvest.
Goats, on the other hand, make for pretty easy harvests, often jumping at the chance to be milked.
So, how, exactly do you start a tribe of transgenic, spider silk-producing goats?
First, you identify and extract the gene responsible for the desired silk (in this case, the golden orb weaver’s dragline silk). Then, you insert that gene into the DNA of goat embryos (among that which prompts milk production), implant them into female goats and wait roughly 150 days to oversee the birth of your unique kids.
When spider-goats (as successful candidates are cheekily referred) begin producing milk, the silk proteins are separated from the milk and spun into silk.
By weight, natural spider's silk is as strong or stronger than steel, while retaining its biodegradable properties. It's long been used by humans as a wound dressing and in catching gish, with more recent technologies in optics, cloth weaving and the creation of spider silk violin strings.
"There's a lot of interest in spider silk fibers because they're stronger than almost any other manmade fiber and they're also elastic," Lewis told Science Nation. "People are interested in them for things like artificial ligaments and artificial tendons, bulletproof vests and even car airbags--something that would allow you to be contained, but not blown back in your seat."
But, replicating the spinning process is a challenge, and until recently, it didn't seem commercially viable. In 2013, a company based out of Germany announced it had found a way to spin fibres with characteristics of insect and arachnid silk combined, making it easy to handle and colour, while increasing the strength above that of the silk we already know and love. It has yet to be commercialized.
And though milking goats is pretty well understood, there is still much to discover about the intricacies of weaving 1500 spider silk strands into fibre.