Fighting the mad cow through genetic engineering

Scientists want to design cattle that will never get the disease.

Popular Sciences

In the last twenty years, up to a million cattle worldwide have been infected with mad cow disease. Only about 200 people died from the human version of the disease - known as Jacob Creutzfeldt - but it is likely that hundreds of thousands of people ate meat that was infected with mad cow disease. Experts fear that thousands of these people will eventually develop the fatal brain disease, which may not appear until many years or even decades later.
Instead of looking for a cure, several research teams are now running a race to try to eradicate the source of the disease and design cattle that will be vaccinated against it. The scientists, including Woo Seok Hwang - a researcher of stem cells and genetic replication from the National University of South Korea in Seoul - and Jim Roble, the chief scientific officer of the biotechnology company Hematech of South Dakota, are leading the efforts to create cattle heads with different prions, or without prions rule. Prions are the mysterious proteins largely responsible for mad cow disease and vCJD.
The prions, which exist in almost all human and animal cells, are generally harmless. Researchers have not yet discovered their exact role; It is possible that they help brain development or sleep - no one knows for sure. However, there is no doubt that when the prions develop mutations and take on new forms, they begin to kill brain cells. The proteins that have developed mutations infect healthy proteins, causing them to also develop mutations and the process unfolds without any control.

Is the public ready for a genetically engineered cow?
Four known groups are working on finding ways to remove the prions from the cow's DNA, or to modify them. However, only one group has so far succeeded in breeding a transgenic cow: Hwang's team announced last spring that it had begun testing a genetically modified cow. The animal has been exposed to mad cow disease and the scientists are testing whether it will contract it. The signs of the disease appear in cows only after at least six months, so the results will be known at the earliest at the beginning of next year. According to Heung, he created four more resistant cows using the same method: He inserted an improved gene into the cow's DNA to create a kind of strengthened prion that does not change its shape even when infected with mutated proteins. Rubel, who was the first to clone a cow - in 1998 - takes a different approach. Instead of inserting a new gene into the cow's DNA, he tries to silence the existing gene, the one that creates the freon in the first place.
If the development of cows resistant to mad cow disease is successful, these will be valuable cattle. The disease caused a lot of damage around the world. So far, 3.5 million cows have been quarantined, and every year millions of cows are tested for fear of contracting the disease. The cost of these activities reaches billions of dollars. The problem is that even if they succeed, the scientists still don't know how to answer another question: how will consumers accept the genetically engineered cows?