Very Sane, Well-Adjusted Cows

Prii-ii-ii-ii-on over yooouuu...

Scientists have genetically engineered a dozen cows to be free from the proteins that cause mad cow disease, a breakthrough that may make the animals immune to the brain-wasting disease.

An international team of researchers from the U.S. and Japan reported Sunday that they had "knocked out" the gene responsible for making the proteins, called prions. The disease didn't take hold when brain tissue from two of the genetically engineered cows was exposed to bad prions in the laboratory, they said.

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The research published in the online journal Nature Biotechnology could be used as a tool that would help researchers better understand similar brain-wasting diseases in humans, Glenn and others said.

Scientists are still mystified by the biological purposes of normal prions, which humans also produce. But they believe that even one prion going bad can set off the always fatal and painful brain disease -- known as variant Creutzfeldt-Jakob disease in humans.

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In the lab, Robl and his colleagues, who included a scientist from the U.S. Department of Agriculture, scraped skin cells from cows and "turned off" the gene that makes prions.
Then, using those cells as a "starter kit," they produced 12 calves through cloning processes -- the fusing of the cells into the eggs of cows....

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But Hematech isn't much interested in producing serum for scientists and has no plans to become a beef producer.

Instead, the company is genetically engineering cows to produce antibiotics and other medicines for people.

The company embarked on the mad cow disease project five years ago to ensure it could produce medicines that were free from the brain-wasting disease. BSE is caused when one misshapen prion prompts normal prions to turn bad, slowly boring lesions in the brain and making infected animals go mad.

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At least 180 people worldwide have died after eating meat infected with mad cow disease in the last two decades. Symptoms can take years to develop.

But scientists are certain the brain-wasting diseases are caused by the misshapen prions, one of the most mystifying particles in biology. No one knows the function of normal prions and the research published Sunday suggests the proteins have little value.

All the prion-free cows the research team created were born healthy, although Robl noted that since they are only two years old they will have to be watched to see if the lack of prions has any future health effects.

"It furthers the mystery of prions, for sure," Robl said.

I'm not sure what I find more intriguing: That mad cow disease can possibly be genetically engineered away, or the other aspect of this experiment - what happens to an animal that can't produce prions? If they do in fact serve some hitherto unknown function, this may be the only way to find out. I just hope the whole process isn't too cruel - I didn't get the impression that Hematech places much of a premium on humane treatment...