June 23, 2008
Duane Kraemer approaches with pride the Angus bull eating hay behind a fence at Texas A&M University. As the veterinary surgeon draws near, the bull snorts and paws the ground.
Healthy as he looks, many Americans would not want to see this bull become steak on their plate. His name, “86 squared”, hints at his origins as the clone of a bull called 86.
The US Food and Drug Administration set off a debate across the food industry when it ruled in January that clones of cattle, pigs and goats were safe to eat. Since then the US Department of Agriculture has asked producers to refrain from introducing milk and meat from clones into the food supply “to ensure a smooth and seamless transition into the marketplace”.
Consumer groups, however, believe that may already be happening as the market outpaces regulation. The offspring of cloned animals are not included in the moratorium, they point out, and producers are already selling semen from cloned animals.
US regulators cannot be certain whether any cloned animals have entered the food supply – for the very reason that they are said to be safe to eat. “There is no way to tell them apart,” says Larisa Rudenko, senior adviser at the FDA’s Center for Veterinary Medicine. “There are no science-based tests to determine whether an animal is a clone.”
With FDA approval, US cloning companies expect interest in their products to grow. Mark Walton, president of ViaGen, the country’s top cloning company, says: “Now that we’ve cleared our biggest hurdle – the FDA’s confirmation that livestock cloning does not affect food safety – our path to profitability is clear.”
The day beef suppliers look to clone cattle that have yielded great steaks may not be far off. “One out of every four steaks doesn’t eat right,” Mr Walton says. “There might be an opportunity in the future to fix that.”
Clones, which are created when a nucleus from the cloned animal is placed in a donor egg from which the nucleus has been removed, are not exact replicas. Most mitochondria, “energy factories” with DNA in them, come from the donor egg. While not predominant in the cells produced, they are present. Environment, nutrition and chance then affect how genes are used.
Dr Kraemer, whose lab has cloned more species than any in the world, says these variables mean a cloned animal is more like a sibling than a facsimile. When his lab cloned the first cat, which was born with different colouring from the animal its cells originated from, people understood “they weren’t getting their animal back”.
More worrying for some who fear they may be eating meat or drinking milk from a cloned animal or its offspring is the higher abnormality rate among clones. A 2002 study found that, of 335 cattle clones, 259 were healthy, meaning 23 per cent were not – three times the percentage among natural-born offspring.