Although the U.S. Food and Drug Administration (FDA) has asked companies that have cloned animals not to introduce the animals, their offspring, or milk or eggs into either human or animal milk supplies, the agency recently orchestrated a series of meetings among academics, food industry representatives and public interest groups to discuss "science-based" safety issues surrounding animal biotechnology.

Conducted by the National Research Council, the late-November meetings were scheduled to target a number of issues, from animal welfare and environmental concerns to the safety of cloned food. The majority of meetings were conducted behind closed doors, and resulting information will be included in a report to FDA.

Earlier this year, FDA began developing policy guidelines on whether cloned animals that are not genetically modified should be tightly regulated like drugs. As an interim measure, the agency urged companies that clone sheep, cows or pigs to file an application with the agency if they wished to sell cloned animals as food.

Among the companies currently involved in animal cloning are PPL Therapeutics, Infigen Inc. and Advanced Cell Technology. In June, an Infigen spokesman indicated that the companies first cloned cattle whose milk might be introduced into the food supply were due to be born last fall. However, the company said it would not release the cattle until it had regulators' support.

Cloning occurs when DNA from and adult cell is deposited in a female egg stripped of its own genetic material. The resulting embryo is then implanted into a surrogate mother.

FDA was planning to issue a position on animal cloning after the National Academy of Sciences had completed a report on potential hazards posed by cloned animals to other animals, human health or the environment. The report is due out early this year.