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2-Plants: Scientific study on GE contamination of Mexican native corn published



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                                  PART I
-------------------------------- GENET-news --------------------------------

TITLE:  Transgenic DNA discovered in native Mexican corn, according to a
        new study be UC Berkeley researchers
SOURCE: University of California - Berkeley, USA, press release
        edited and sent by Agnet, Canada
DATE:   November 28, 2001

------------------ archive: http://www.gene.ch/genet.html ------------------


TRANSGENIC DNA DISCOVERED IN NATIVE MEXICAN CORN, ACCORDING TO A NEW STUDY 
BY UC BERKELEY RESEARCHERS

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.


                                  PART II
-------------------------------- GENET-news --------------------------------

TITLE:  Greenpeace, world scientists call for action to save Mexico's corn
        from genetic contamination
SOURCE: Greenpeace USA, Press Release
        http://www.greenpeaceusa.org/media/press_releases/01_11_28.htm
DATE:   November 28, 2001

------------------ archive: http://www.gene.ch/genet.html ------------------


Greenpeace, World Scientists Call For Action To Save Mexico's Corn From 
Genetic Contamination

Washington, DC, November 28, 2001  The first peer-reviewed scientific 
paper documenting the scope of contamination of Mexican corn by genetically 
engineered varieties will be released today by the journal Nature. In a 
letter to U.S. EPA Administrator Christine Whitman and Agriculture 
Secretary Ann Veneman, Greenpeace called upon the U.S. government to 
immediately halt the export to Mexico of genetically engineered corn as a 
first step to protecting that country's native corn varieties from further 
genetic contamination.

"With the center of genetic diversity for one of the world's staple food 
crops already contaminated, the U.S. must act immediately and aggressively 
to protect it," said Dr. Doreen Stabinsky, science advisor to Greenpeace. 
"Contamination from genetically engineered corn to local corn varieties in 
Mexico could cause their extinction. If this diversity is lost, future food 
security is at risk."

Environmentalists, evolutionary biologists, and plant breeders are all 
concerned about the implications of the contamination for corn diversity. 
In a recent statement obtained by Greenpeace, over 80 scientists and plant 
breeders call upon "all governments to employ all means possible to prevent 
the contamination of Mexican maize and its wild relatives by genetically 
engineered corn varieties." Plant breeders rely on the genetic diversity of 
local varieties found in a crop center of origin - Mexico is an important 
center of origin for corn. In the U.S., the EPA currently prohibits the 
commercial growing of genetically engineered cotton in areas where wild 
relatives are found to prevent such gene flow from causing the extinction 
of those native species.

"The EPA is engaged in an unacceptable double-standard by protecting our 
crop diversity but failing to take steps to protect corn genetic resources 
in Mexico," added Stabinsky. "Our future corn crops rely on genes found in 
Mexican local varieties."

In the letter to the heads of the EPA and USDA, Greenpeace reminded them 
that "under the North American Plant Protection Organization (NAPPO) 
Cooperative Agreement, the U.S. government has agreed to work with the 
governments of Mexico and Canada to 'foster the preservation of plant 
resources in North America.'"

Mexican authorities have known about the contamination for several months. 
Investigation by the Mexican National Institute of Ecology in the states of 
Oaxaca and Puebla found contaminated varieties in 15 of 22 communities 
tested, at levels from 3 to10 percent.

"As the source of the contamination, the United States should be the first 
to step forward and immediately halt exports of genetically engineered corn 
to Mexico," said Hector Magallon Larson, genetic engineering campaigner 
with Greenpeace Mexico.

Dr. Stabinsky will deliver a similar message at an international scientific 
conference, "LMOs and the Environment," beginning tomorrow in Durham, NC, 
and sponsored by the U.S. government and the Organization for Economic 
Cooperation and Development (OECD).

The letter to the EPA and the statement from the 80 scientists can found 
below. A copy of the Nature article can be obtained by calling Bronwyn 
Murray at (202) 626-4956.



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