What is it?
Recently, a research team from the University of Wyoming have developed a new way of incorporating the silk generating gene of a spider into goats. Thus creating the web spinning goat. The goats are genetically modified to have the webs collected from their milk are planned to be used for many different purposes like for medical reasons.
History
Spider silk is known to be strong and it substantially stronger than any other man-made fiber in the same quantity. For years scientists and researches have being trying different ways to mass produce spider silk. Unfortunately, past efforts to harvest spider silk have proved fruitless Spider farms have been tried but have failed each time because spiders are very territorial and they ended up killing each other. Because of this dilemma, researchers have developed the idea of inserting the spider gene of silk spinning into goats.
How are the goats produced?
The web spinning genes that spiders naturally have are placed into female goats so when they lactate the protein found in the spider silk is produced. Spiders produce 6 types of silk and scientists have identified the silk type called the "dragline" silk, or the outer strand to be the most durable of all the different types.
The scientists do this by inserting the gene that codes for producing the dragline silk into the DNA of a female goat. So when the goat reproduces her offspring will most likely express the silk producing gene. An embryo, or a fertilized egg, is taken and they insert a few copies of the gene into the egg using tiny metal inserters. Then the spider gene becomes apart of one of the chromosomes. These genetically modified goats are now 1/70,000 spider. (Lewis)
There is a gene that helps with gene expression by only expressing traits in the mammary glands when the goat is lactating. This means that the goat will only produce silk when it is lactating/being milked (Lewis). The silk milk idea works because the method that spiders use to make their silk proteins is somewhat similar to how mammals make their milk proteins. The only difference between the genetically modified goats milks from a normal goat's milk is that the spider silk's protein is present in the GM goat's milk.
To obtain the silk, scientists simply harvest the milk from the goat. The milk is then taken to a laboratory where the spider protein is filtered out. This yields a thick, syrupy substance called spindo, which is very similar to what is actual inside the silk glands of spider. What scientists do to mimic the spinnerets, or the holes that spiders eject their silk from, its to make tiny holes in stainless steel that is attached to vial of spindo. The spindo is then ejected from the wholes and the silk is formed. The proteins line up and snap together when exposed to oxygen. Unfortunately, this silk is only 30% of the strength of genuine spider silk and currently scientists are contemplating on combining different types of spider silk proteins to create a more durable silk. (Lewis)