ngin - Norfolk Genetic Information Network

29 November 2001


"This is very serious because the region where our samples were taken are known for their diverse varieties of native corn, which is something that absolutely needs to be protected. A wealth of maize varieties has been cultivated over thousands of years in the Sierra Norte de Oaxaca region, providing an invaluable ‘bank account’ of genetic diversity. Genetically diverse crops are less vulnerable to disease, pest outbreaks and climatic changes. We can't afford to lose that resource."
- Researchers in microbial ecology in the Department of Environmental
Science, Policy & Management at UC Berkeley's College of Natural Resources

1. Genetic diversity is at stake - BBC News Online url
2. GM corn DNA found to have spread to Mexican maize - AP


1. Mexican study raises GM concern: Genetic diversity is at stake, say campaigners

By BBC News Online's Ivan Noble
Wednesday, 28 November, 2001, 19:49 GMT


2. Genetically modified corn DNA is found to have spread to Mexican maize

The Associated Press [shortened]
28 November 2001

DNA from genetically modified corn has found its way into native corn varieties growing in remote southern Mexico, heightening fears about the dangers of bioengineered crops.

Scientists fear the accidental spread of laboratory-inserted genes could give some plants an advantage that would allow them to crowd out other varieties, reducing the world's biological diversity.

"The benefits of these crops don't outweigh the enormous risks to food security," said David Quist of the University of California at Berkeley, one of the researchers who reported the findings in Thursday's issue of the journal Nature.

Diversity is prized by scientists as a hedge against diseases, pests and climate change. While some plant strains may be vulnerable to one disease, for example, others may have natural immunity that enables them to survive.

"We can't afford to lose that resource," said Ignacio Chapela, a co-author of the study.

Four of six samples of native criollo corn taken last year from fields in Mexico's mountainous Oaxaca region were found to contain a genetic "switch" commonly used in genetically engineered plants, the researchers reported.

In addition, two of the samples were found to have another DNA segment commonly inserted by genetic engineers. And one sample contained a commonly inserted gene that prompts the plant to produce a poison effective against the European corn borer, a pest that can harm crops.

The researchers said the discovery was surprising because Mexico imposed a moratorium on genetically engineered corn in 1998. Before that, the closest government-approved plantings of such corn were at least 60 miles from the sample sites.

Scientists could not determine exactly where the foreign DNA came from. But Quist said the researchers suspect imported genetically modified corn was handed out by a government agency as food and may have been planted by recipients near their traditional crops.

They do not believe cross-pollination happened over long distances because corn pollen is heavy, does not travel far and is short-lived.

The unintended DNA mixing is not the first involving a genetically engineered plant. Still, it highlights the need to carefully control an emerging field in which plants are being equipped with new genes to let them produce medicines and other compounds, the researchers said.

Quist said, for example, that plants are now being developed to produce compounds that act as spermicides. "Just think if that gets out into the environment and has a negative impact on people's fertility," he said. "It's obvious there are reasons to be concerned until we have greater information on what the impact will be about the release of this technology."

Rebecca Goldburg of the Environmental Defense Fund said the findings show that decisions on whether to approve genetically modified plants should not be made lightly.

"I think the primary message of this article is that large-scale production of genetically engineered crops is going to have an irreversible effect because it is impossible, or virtually impossible, to contain genetic material once it is put into crops that are planted on a wide scale," she said.



November 28, 2001
University of California - Berkeley press release

Berkeley - Some of Mexico's native varieties of corn grown in remote regions have been contaminated by transgenic DNA, a finding that has both surprised and dismayed the University of California, Berkeley, researchers who made the discovery.

"This is very serious because the region where our samples were taken are known for their diverse varieties of native corn, which is something that absolutely needs to be protected," said Ignacio Chapela, assistant professor of microbial ecology in the Department of Environmental Science, Policy & Management at UC Berkeley's College of Natural Resources.

In the study, published Thursday (Nov. 29) in the journal Nature, Chapela and David Quist, lead author and UC Berkeley graduate student in environmental science, policy and management, compared indigenous corn with samples known to be free from genetic engineering as well as with genetically modified varieties.

The native corn, or "criollo," samples were taken from four fields in the remote, mountainous region of Sierra Norte de Oaxaca. Control samples that had not been genetically modified came from blue maize grown in the Cuzco Valley in Peru, and also from a collection of seeds from the Sierra Norte de Oaxaca region taken in 1971, before the advent of transgenic crops.

Using highly sensitive polymerase chain reaction (PCR)-based tests, the researchers checked for various elements of transgenic DNA constructs used when bioengineered genes are introduced into a plant genome.

They found no signs of transgenic DNA in the Peru and 1971 seed collection. In the criollo samples, however, four out of six samples tested showed weak but clear evidence of p-35S, a promoter from the cauliflower mosaic virus widely used in transgenic crops. When they sequenced the DNA of the transgenic-positive criollo samples, the researchers found that the CMV promoter matched those used in commercial transgenic crops.

The presence of the nopaline synthase terminator sequence (T-NOS) from Agrobacterium tumefasciens, another telltale sign of transgenic contamination, was detected in two of the six criollo samples tested. One criollo sample tested positive for the actual cry-1A gene of Bacillus thuringiensis (Bt), the insecticidal bacterium that kills pests feeding on corn.

"I repeated the tests at least three times to make sure I wasn't getting false-positives," said Quist. "It was initially hard to believe that corn in such a remote region would have tested positive."

Chapela and Quist said the contamination likely came from multiple pollinations over time. They were able to identify the DNA fragments flanking the CMV promoter sequence through inverse PCR tests. Those fragments were diverse, suggesting a random insertion of the transgenic sequence into the maize genome.

"If this contamination was the result of a single gene transfer event, we would expect to find the transgenic DNA in a consistent location on the criollo genome," said Quist. "Instead, we're finding it at different points along the genome."

The researchers first detected the transgenic DNA in October 2000 while working with the Mycological Facility in Oaxaca, a locally-run biological laboratory where Chapela serves as the scientific director.

Soon after the initial discovery of the transgenic contamination, Chapela alerted the Mexican government, which then proceeded to conduct its own tests. Reporting the results in a September press release, Mexico's Ministry of the Environment and Natural Resources found transgenic DNA in three to 10 percent of the Sierra Norte de Oaxaca maize, supporting the results of the UC Berkeley researchers.

Just how the contamination occurred remains a puzzle. Agricultural experts and proponents of biotech crops maintain that corn pollen is characteristically heavy, so it doesn't blow far from corn fields by the wind. Chapela said this assumption may need to be reevaluated in light of the recent findings in Mexico.

In addition, Mexico imposed a moratorium in 1998 on new plantings of transgenic maize. The closest region where bioengineered corn was ever known to have been planted is 60 miles away from the Sierra Norte de Oaxaca fields, said Chapela.

"It's not clear if the moratorium was poorly enforced, or if the contamination occurred before the moratorium was enacted," said Chapela. While new plantings are banned in Mexico, it is still legal to import biotech corn into the country. "Whatever the source, it's clear that genes are somehow moving from bioengineered corn to native corn," he said.

Such a prospect is almost certain to fuel the already contentious debate over the use of genetically modified crops. Proponents of transgenic agriculture say biotechnology helps to increase crop yields for feeding a rapidly growing world population, improve the food's nutritional value and reduce the use of pesticides. Opponents say not enough is known about the health and ecological effects of biotech crops and that the risks outweigh the benefits.

To date, more than 30 million hectares of transgenic crops have been grown, according to "Transgenic Plants and World Agriculture," a white paper published in 2000 by a group of seven national science academies around the world, including the U.S. National Academy of Sciences and the Royal Society of London.

Genes from genetically modified crops that spread unintentionally can threaten the diversity of natural crops by crowding out native plants, said Chapela. A wealth of maize varieties has been cultivated over thousands of years in the Sierra Norte de Oaxaca region, providing an invaluable "bank account" of genetic diversity, he said.

Chapela added that genetically diverse crops are less vulnerable to disease, pest outbreaks and climatic changes. "We can't afford to lose that resource," said Chapela.



Embargo:  1900 hours, Wednesday 28 November 2001

Halt this reckless experiment now says FOE

Friends of the Earth is calling for an immediate global moratorium on the growing of GM crops [1] after new research revealed that wild maize in Mexico has been contaminated with GMOs.  The results are revealed today in the science journal Nature .

Researchers in Mexico found that wild maize in a remote area of Mexico was contaminated with genetically modified (GM) material - despite a moratorium on growing GM maize since 1998.  The source of the GM contamination is unknown.  The remote location of the wild maize strains suggests that cross-pollination may have taken place over considerable distances.  Maize originates in Mexico. All commercial varieties were originally bred from this wild stock.

The revelation raises concerns about pollution from GM crop trials in the UK. Of the GM crops currently being tested in the UK oilseed rape and beet crops have wild relatives [2].

Pete Riley, Real Food Campaigner at Friends of the Earth, said: These findings are deeply disturbing and highlight the huge gamble the biotech industry is taking with nature.  The long-term implications of allowing GM crops to contaminate wild plants are unknown and will be almost impossible to reverse.  This is why Governments around the world should halt the dangerous experiment of growing GM crops outside."

[1] The Biosafety Protocol (or Cartegena Protocol) was signed in Montreal in 1999 and allows states to control the import of GMOs if their environment is under threat.  Britain has signed - but not yet ratified - the protocol.  The USA, the largest exporter of GM maize for food, animal feed and seed hasn't even signed it.
 [2] Other centres of biodiversity that could be contaminated with GM materials are the Andes (potatoes), China (soya beans) and Thailand (rice).

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