Many of us are concerned by the possible risks of agricultural biotechnology. For example, when you grow transgenic crops, can their modified genes alter wild varieties of similar wild plants? The latest issue of the California Agriculture magazine carries several articles focusing on transgenic crops, fish and animals. And some discoveries are alarming: "one of the world's most important crops, sorghum, spontaneously hybridized with one of the world's worst weeds, johnsongrass, even when they were grown up to 330 feet apart; furthermore, the two plants are distinct species with different numbers of chromosomes." Read more for selected excerpts of these three important research papers.
California Agriculture is a peer-reviewed journal reporting research, reviews and news from the Division of Agriculture and Natural Resources of the University of California. Its latest issue contains several articles about transgenic crops, fish and animals which show that "crop transgenes wander in the environment" and asks the question: "But is this is cause for worry?"
Here is a link to the abstracts of this July-September 2006 issue.
Let's start with the paper about transgenic crops, "When crop transgenes wander in California, should we worry?" (PDF format, 10 pages, 1.08 MB). Here is the introduction of this article from Norman C. Ellstrand.
The movement of transgenes into populations for which they are not intended remains a primary concern for genetically engineered crops. Such gene flow in itself is not a risk. However, we know that the transfer of genes from traditionally improved crops into wild populations has already resulted, on occasion, in the evolution of weeds more difficult to control, as well as an increased extinction risk for rare species. Just like traditional crops, genetically engineered crops could occasionally create the same problems.
Before going further, do you have an idea of what kind of genetically enhanced products exist today? Below is a picture that will show you that there are many food products genetically engineered (Credit: Stephen Ausmus, USDA-ARS).
Here is the caption of this photograph: "Genetic engineering has been used to modify all of the crops and products shown, although most are not commercially available. The environmental risks of growing transgenic crops could include pest resistance and unintended effects on nontarget species, such as increased weediness among similar wild plants."
And here is a quote about the future of plant biotechnology.
The face of plant biotechnology is rapidly changing. Dozens of genetically engineered crop species have been fieldtested. Crops field-tested under U.S. Department of Agriculture/Animal and Plant Health Inspection Service (USDA APHIS) notification or permit are required to be grown with some level of containment (NRC 2002). If the growers comply with those regulations, fieldtests should not present an opportunity for transgene escape.
Now, let's move from plants to fish with the second paper, "Careful risk assessment needed to evaluate transgenic fish" (PDF format, 6 pages, 599 KB). Here is the beginning of this paper from Alison L. Van Eenennaam and Paul G. Olin.
The reproductive biology of fish makes them particularly amenable to genetic manipulation. A genetically engineered or "transgenic" Atlantic salmon is currently undergoing federal regulatory review, and international research is being conducted on many other species. The innate ability of fish to escape confinement and potentially invade native ecosystems elevates the ecological concerns associated with their genetic modification.
The following picture of a large-scale fish farming cage off Hawaii illustrates the problem (Credit: Kona Blue, a commercial project from Black Pearls, Inc.). "The containment of transgenic fish will be a critical component of any commercialization strategy, to prevent interbreeding with wild, native fish."
And what can we expect in the future?
In the United States, the use of transgenic fish is federally regulated under the Food, Drug and Cosmetics Act, with the FDA’s Center for Veterinary Medicine (CVM) asserting primary jurisdiction over transgenic animals. Transgenic animals for production fall under CVM regulation as new animal drugs. To date, no transgenic animals have been approved for use as human food, although the Aqua Bounty transgenic Atlantic salmon has been under regulatory review for more than 5 years.
In the near term, it is the marketplace more than the science that will decide the fate of new technologies and acceptability of certain risks. Food retailers and even farmers may be unwilling to stock the transgenic fish and risk having their market become the target of an organized anti-biotech campaign [like the ones happening today in Europe.]
After crops and fish, it's time to look at the third paper, "What is the future of animal biotechnology?" (PDF format, 8 pages, 896 KB). Here is the introduction of this paper from Alison L. Van Eenennaam.
Animal biotechnology encompasses a broad range of techniques for the genetic improvement of domesticated animal species, although the term is increasingly associated with the more controversial technologies of cloning and genetic engineering. Despite the many potential applications of these two biotechnologies, no public or private entity has yet delivered a genetically engineered food-animal product to the global market.
The paper includes several pictures of cloned animals, including the one below of Leslie Lyons, associate professor in the UC Davis School of Veterinary Medicine, and who "studies cats to investigate the genetic bases for inherited diseases in animals and humans. [...] Kiwi and Kashmir [, shown here,] are purebred Oriental shorthair kittens that carry a lympho-sarcoma gene." (Credit: Debbie Aldridge, UC Davis)
And here are some excerpts from the conclusion of this paper.
Given that the term "animal biotechnology" elicits a negative public reaction in the absence of any other information, scientists have an obligation to engage in the public discourse by articulating the science-based risks and benefits of their research, in addition to the ethical issues occasioned by their work. Polarizing the issue of genetic engineering of animals into "all is permitted" or "nothing is permitted" prevents rational social progress on the issue.
Effective and responsible communication among scientific, community, industry and government stakeholders is essential to reach a societal consensus on the acceptable levels of risk for specific products of animal biotechnology, and to determine which set of values will ultimately be applied to decide the acceptable uses of animal biotechnology.
After reading these excerpts -- or the full papers -- should we worry? Maybe not, but it would be wise to look at what happens in the labs.
Sources: California Agriculture magazine, Volume 60, Number 3, July-September 2006; and various web sites
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