March 1, 2004
Timothy M. Beardsley
Government overseers of biotechnology, as well as developers of genetically engineered organisms, should pay careful attention to the exhaustive January report from the National Research Council (NRC) on biological techniques for preventing the spread of engineered genes in nature (see http://books.nap.edu/catalog/10880.html). The technology for creating not only plants but also animals and microbes altered to include beneficial traits is advancing by leaps and bounds. Because organisms have an annoying propensity to escape from purely physical confinement — or to spread their genes by crossing with wild relatives — "bioconfinement," as the NRC terms biological approaches, has great potential to reduce the risk that engineered genes might contaminate the food supply or interfere with natural populations. So far, however, efforts to develop bioconfinement techniques have not kept pace with the transgenic organisms themselves.
Currently, worries focus mainly on modified plant crops that might spread engineered genes for herbicide or pest resistance to weedy relatives. Spontaneous hybridization of (nontransgenic) crops and their wild relatives has led to the evolution of several weeds, and biologists know it is extremely difficult to limit an invasion once one has taken hold. Bioconfinement mechanisms such as induced sterility or suppression of pollen production could provide an important safety backup for when mechanical confinement fails. Likewise, engineered fish and shellfish now in development could outcompete natural species if they escape, but they might be bioconfined by turning them into triploids, which are sterile. Bioconfinement of insects and microbes engineered to curtail the spread of disease or improve industrial processes is also a possibility, but little research has been done on suitable techniques.
The NRC's report stresses that developers should plan a comprehensive bioconfinement strategy that takes account of the degree of threat that an escape would pose. Some escapes would seem to pose little risk, but others — the spread in nature of genes for pharmaceutical production, for example — would be highly undesirable. Although no single bioconfinement method is likely to be foolproof, multilayered methods incorporated early in the development of a novel engineered organism could make acceptable a deployment that might otherwise seem chancy. As bioconfinement methods are still not well advanced, the field beckons. Time could be of the essence: At least one company has already engineered crops to produce veterinary medicines and is looking to initiate field tests. And since nonhuman organisms are no respecters of national borders, there is a compelling case for international cooperation on regulatory approaches.
The hostility to genetically modified organisms in Europe proves that mistrust of biotechnology can, in a democracy, delay — if not stop in its tracks — the adoption of technologies with beneficial potential. An updated, transparent approach to regulation stateside could do a lot to ensure that unpleasant surprises do not sow the seeds of mistrust on this side of the Atlantic, where millions of acres of transgenic crops are already under cultivation. Happily, the US Department of Agriculture, which requested the NRC report, seems open to considering environmental effects and
bioconfinement in its regulatory approach. Biologists have a great opportunity to step up to the plate.
Timothy M. Beardsley