Researchers are spinning spider silk from goats' milk
25 May '10
6 min read
While spiders make some people flinch, there's no escaping the appreciation for their masterful web construction.
"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," says Randy Lewis, professor of molecular biology at the University of Wyoming in Laramie.
Since ancient times, there's been a fascination with spider webs because of that combination of qualities. There's folklore going back to the first century A.D., when spider webs were used as dressings for wounds. Twenty-first century experts are looking at silk for many of the same reasons.
"So there are a lot of applications," continues Lewis. "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, whether it's for super-strong sutures for surgery or an air bag, how do you come up with enough raw material? Spider farms have been tried, but arachnids tend to kill each other.
"The problem is that the spiders are territorial, and so no matter what you do, there are only a certain number of spiders you can put in a certain space," says Lewis.
That's where the goats come in.
With help from the National Science Foundation (NSF), Lewis and his team have figured out a way to put the spider's silk-making genes into goats.
"So what we've done is we've actually cloned the genes for the protein that makes up every one of the spider silks. They make six different kinds of silk and a kind of glue. We know, in particular, (there is) a silk called dragline silk that they use to make the framework of a web, that's the one that most people are interested in," he explains.
Lewis, working with Nexia Biotechnologies, has put those silk genes in goats, in a way that they only make the protein in their milk.
"When the goats have kids, and they start lactating, we collect the milk, and we can purify that spider silk protein in much, much higher quantities," says Lewis.
This academic "Spiderman" is a hands-on guy, whether it's milking goats or wrangling spiders. The halls of his labs are covered with spider balloons and posters of the Spiderman from comic book fame. There are also crayoned, thank you notes from school children who have seen some of the spiders up close.
At the University of Wyoming Animal Science Livestock Center, a few miles from the main campus, Lewis is surrounded by seven lively and inquisitive kids, but these kids are goats that were born in early February 2010.
"We had three sets of twins and one single. We've done the blood tests on them, so we know that three of them do have the silk gene, and four of them do not. There are only so many copies of the gene, so it's like any other genetic factor, a certain percentage is going to getit, and some of them aren't," he explains.