'Designer' chickens that could save lives

Scientists have created a breed of designer chickens with eggs that can produce life-saving drugs.The breakthrough could help the fight against diseases such as cancer and dramatically cut the cost of treatments.

But it will worry opponents of the genetic modification techniques the scientists used. The 500-strong flock was bred at Edinburgh's Roslin Institute, the birthplace of Dolly, the cloned sheep.

The chickens' DNA was altered (changed) so that their eggs contained complex medicinal proteins.

The proteins can be extracted (taken out) to make drugs for humans.It is the first time scientists have successfully manipulated (managed) the birds' DNA so that their characteristics are passed down the generations. Previously, the ability to make the valuable proteins had vanished in a generation or two.

The scientists had also announced the successful production of anti-cancer proteins in the whites of eggs.

Since then, they have made dramatic strides which could lead to the creation of egg drug factories.

Such a development would slash (cut) production costs.

At present, disease-beating proteins are mainly created in vats of bacteria or other cells that have been genetically modified.

This makes extracting the relevant proteins expensive and difficult. The Roslin scientists used some of the GM chickens to create interferon. A drug based on this human protein is widely used to treat multiple sclerosis.

The chickens have also been used to create an antibody that could tackle skin cancer. The avian transgenic manufacturing project is a joint venture between the Roslin Institute and the biotechnology firms Viragen and Oxford BioMedica.Karen Jervis, of Viragen Scotland, held out the prospect of many more treatments.

"We have bred several generations of chickens so far, and they all keep producing high concentrations of pharmaceuticals", said Dr Jervis. "This is potentially a very powerful new way to produce specialised drugs. We chose two candidates, but we have got others coming through.

"What we want is to produce as many possibilities as we can to show that we can apply the technology to many drugs. Theoretically, there is no restriction on the type of drugs that can be produced."

It is likely to be several years before the breakthrough could have a commercial application.

Any resultant drugs would have to go through the rigorous (severe)trial procedures faced by any new drug. This can take six years. Some scientists are cautious (careful) about the development and say similar advances have been trumpeted for nearly two decades.

The world's most successful transgenic animal so far has been a pet called the 'glofish'. This tropical fish was genetically modified with the DNA of a sea anemone and a jelly fish to give it fluorescent skin.

But Dr Barbara Glenn of Bio. which represents the American biotech industry said that the Roslin research would pave the way for more breakthroughs.

"This technique is simply a way of producing human proteins, which is why it is applicable to so many diseases", she said.

Daily Mail