| WASHINGTON -- The possibility of certain genetically engineered fish and
other animals escaping and potentially introducing engineered genes into wild
populations tops the list of concerns associated with advances in animal biotechnology,
says a new report from the National Academies' National Research Council. On the
other hand, no evidence yet exists that products from cloned livestock are unsafe
for human consumption, although the committee that wrote the report found it difficult
to identify concerns without additional information about food composition, which
could be collected using available analytical tests.
The report was requested by the Food and Drug Administration as it prepares
to rule on the safety of certain animal-biotechnology products, particularly cloned
cattle. The committee was asked only to identify science-based concerns; it was
not asked to identify potential benefits from animal biotechnology or to make
policy recommendations.
"As is the case with any new technology, it is almost impossible to state
that there is no concern, and in certain areas of animal biotechnology we did
identify some legitimate ones," said committee chair John G. Vandenbergh,
professor of zoology, North Carolina State University, Raleigh. "By identifying
these concerns, we hope we can help this technology be applied as safely as possible
without denying the public its potential benefits."
The committee said the greatest concern is the ability of certain genetically
engineered organisms to escape and reproduce in the natural environment. Genetically
engineered insects, shellfish, fish, and other animals that can easily escape,
that are highly mobile, and that become feral easily are of particular concern,
especially if they are more successful at reproduction than their natural counterparts.
For example, it is possible that if transgenic salmon with genes engineered to
accelerate growth were released into the natural environment, they could compete
more successfully for food and mates than wild salmon.
By creating transgenic animals with genes from another species, or by removing
or "turning off" genes, animals can be produced to grow bigger and more
rapidly, or possess traits beneficial to humans, such as meat with more protein
and less fat, eggs with less cholesterol, milk containing pharmaceutical products,
or even tissues and organs suitable for human transplantation. And through somatic
cell nuclear transfer -- the technique used to clone Dolly the sheep -- scientists
can create an almost identical copy of an adult animal with desirable traits.
The owners of a few hundred cows cloned this way in the United States have been
asked by FDA to hold off selling the cows' milk and meat, or breeding them, pending
regulatory approval.
In transgenic animals developed for human consumption, there is a low probability
that a few new proteins expressed when genes are inserted from another species
may trigger allergic or hypersensitive reactions in a small, but unknown, percentage
of people. The potential for allergenicity is difficult to gauge, however, since
it can only be detected once a person is exposed and experiences a reaction. While
a reaction will be recognizable, as it is with well-known allergens like peanuts
and shellfish, the uncertainty surrounding new proteins and potential impact on
consumers who may be allergic is serious enough to elicit a moderate level of
concern, according to the committee.
Animals genetically engineered to produce non-food products, such as cows that
produce drugs in their milk, are not intended to enter the food supply. But the
committee said there are grounds for concern that adequate controls be in place
to ensure restrictions on the use of carcasses from such animals. In at least
one instance, meat from the carcasses of such animals was used to make a food
product.
The applications of biotechnology may someday reduce the number of animals
needed for food and fiber production, but they also can have adverse effects on
the welfare of animals, the committee noted. For example, calves and lambs produced
through IN VITRO fertilization or cloning tend to have higher birth weights and
longer gestation periods, which leads to difficult births often requiring caesarian
sections. In addition, some of the biotechnology techniques in use today are extremely
inefficient at producing fetuses that survive. Of the transgenic animals that
do survive, many do not express the inserted gene properly, often resulting in
anatomical, physiological, or behavioral abnormalities. There is also a concern
that proteins designed to produce a pharmaceutical product in the animal's milk
may find their way to other parts of the animal's body, possibly causing adverse
effects.
Although the committee was not asked to make any policy recommendations, it
suggested that the current regulatory framework may not be adequate given that
the responsibilities of federal agencies for regulating animal biotechnology are
unclear in some respects.
The study was sponsored by the Food and Drug Administration. The National Research
Council is the principal operating arm of the National Academy of Sciences and
the National Academy of Engineering. It is a private, nonprofit institution that
provides science and technology advice under a congressional charter. A committee
roster follows.
The report ANIMAL BIOTECHNOLOGY: SCIENCE-BASED CONCERNS is available on the
Internet at HTTP://WWW.NAP.EDU. Copies will be available for purchase this fall
from the National Academy Press; tel. (202) 334-3313 or 1-800-624-6242. Reporters
may obtain a pre-publication copy from the Office of News and Public Information
(contacts listed above).
[This news release and the report are available at HTTP://NATIONAL-ACADEMIES.ORG
|
