Clone chops?

Prompted by inquiries from biotech firms, both the US Food and Drug Administration (FDA) and a Canadian federal government interdepartmental working group are evaluating the ramifications of meat from cloned animals one day arriving in supermarkets. "We know the technology is being developed. We know that companies are working on cloned animals. We know these are coming down the pipeline," working-group member William Yan of Health Canada told The Scientist. Stephen Sundlof, director of the FDA's Center for Veterinary Medicine echoed the warning: "We knew about Dolly the sheep and now that technology is on the verge of being commercialized."FDA is expected to issue a white paper on the topic next month. Health Canada has no formal deadline for a decision, said Yan. Due to the expense of producing such animals regulators are not anticipating that shoppers will be able to buy leg of clone for a roast or serve up a glazed cloned ham anytime soon. Rather, meat and possibly milk will likely first come from the offspring of clones, conceived naturally or through artificial insemination. But before regulators will let cloned meat and dairy products onto the market they will have to answer a number of health, environmental and animal-welfare concerns, so Health Canada put together a working group with members from the country's Institutes of Health Research, as well as the country's departments of Agriculture, Fisheries and Environment. Among the issues they are considering are the human health implications of subtle differences between clones and originals. "By definition one expects a clone to be an exact copy," said David Trus, a working group member and geneticist at Agriculture and AgriFood Canada. "The kinds of clones we have, at the detailed molecular level, are not exact copies. It's not the same animal. So one of the issues we have to look at is how different is this 'exact copy.'"One of the differences whose impact must be considered, according to Trus, is the fact that a clone's mitochondrial DNA comes not from its genetic "parent," but from the egg of a host animal.Another problematic epigenetic factor is methylation, the process by which methyl groups attach to DNA, which depends on contributions from both sexes. "So if you have genetic material coming from one sex it looks like you don't exactly get correct methylation occurring and the downstream effects are not fully clear at this point," said Trus. But the economic potential from cloned animals is great according to Mike Wanner, president of ProLinia Inc. of Athena, Georgia, one of several biotechs investing in developing cloned cattle and pigs in anticipation of bringing cloned meat to market. "Everyday we're improving the process and making it more efficient," he said. Wanner foresees the eventual cloning of high-producing pigs and cattle, possibly also transgenically enhanced with disease-resistance or fat-lowering genes. He estimates the potential market for this genetically-enhanced beef and pork to be US$2 billion.Regulatory authorities will first have to be assured of the safety of such procedures. In a report on safety issues in animal biotechnology commissioned by FDA and issued last August by the National Academies of Science, authors wrote, "To date, there are no published comparative analytical data assessing the composition of meat and milk products of somatic cell clones, their offspring, and conventionally bred individuals." Acknowledging that without any data to go on one way or the other, the committee concluded, "Currently there is no evidence that food products derived from adult somatic cell clones or their progeny pose a hazard."Eventually, regulatory agencies will probably approve the use of cloned livestock and their progeny predicted John Walton, professor of animal science at the University of Guelph in Ontario. "You would have a hard time coming up with objective science that their progeny are in some way harmful or are a danger to human health and welfare because "they're almost normal," said Walton.

Clone chops?

US and Canada considering whether to allow duplicate little piggies to go to market.

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