January 2, 2007

Researchers create BSE-immune cattle

Scientists have genetically engineered the first cattle in the world to be free from the proteins that cause mad cow disease, a breakthrough that might make the animals immune to the brain-wasting disease.

A team of experts from Japan and the US took the breed of Holstein cows to genetically engineer calves without a vital protein, known as a prion.

Mad cow disease, or bovine spongiform encephalopathy (BSE), is caused when damaged prions spread to an animal's brain tissue. It then collapses the cow's central nervous system.

The prion-free cattle or GM cows are identical to normal cows in every other way, but for the missing prion.

Following an outbreak of the BSE in the UK in 1996, millions of cattle were slaughtered and beef bans were imposed on exported British beef around the world.

The breakthrough could offer another layer of security to people concerned about eating infected beef, although any food derived from genetically engineered animals must first be approved by the Food and Drug Administration.