New study confirms GM contamination of Mexican corn
2.New study points to GM contamination of Mexican corn
NOTE: The publication of this study* confirms the news published by Nature last November - Quist and Chapela were right about GM contamination of native varieties of maize in Oaxaco, Mexico.
When Nature published the original Quist and Chapela paper in 2001, they came under an immediate firestorm of abuse from pro-GM scientists as the result of a campaign of incitement on CS Prakash's AgBioView listserv. We subsequently showed this campaign to have been directly orchestrated by Monsanto and its internet PR firm Bivings.
At one point Prakash's list members were even encouraged to contact UC Berkeley to demand that Chapela either hand over his maize samples for independent verification or be sacked. The implication was one of fraud, with Fellow of the Royal Society, Tony Trewavas demanding to know whether researchers like Chapela were "free to fiddle any data they like in the 'greater' cause."
When Chapela was subsequently refused tenure at Berkeley, many saw this as part of the vendetta against him because of his research findings. Even though the Mexican government had confirmed the findings, when a subsequent paper was published in 2005 that failed to find contamination in the same area, Monsanto, Prakash and co. were cock a hoop: "Mexican and U.S. scientists have now positively confirmed that biotech traits are not present in native landraces of maize in Oaxaca," editorialised Prakash in a piece on his listserv headed "Duh.... No GM Genes in Mexican Corn".
"Everyone in Mexico," Prakash went on, "especially in the rural communities where a lack of information has produced concerns, should be made aware of these new findings... Many news reporters are also scratching their heads. London's Telegraph blares today 'Worst GM Pollution Incident Vanishes' while it really should have been 'The GM Incident that Never Was'."
Now, nearly 8 years after the publication of the original paper, the new paper in Molecular Ecology* shows Quist and Chapela had it right. That, of course, also means that for 8 years Monsanto and its supporters managed to divert attention by muddying the waters with controversy.
*Transgenes in Mexican maize: molecular evidence and methodological considerations for GMO detection in landrace populations
Molecular Ecology, Volume 18 Issue 4, Pages 750 - 761
1.New Study Finds GM Genes in Wild Mexican Maize
New Scientist, February 21 2009
Now it's official: genes from genetically modified corn have escaped into wild varieties in rural Mexico. A new study resolves a long-running controversy over the spread of GM genes and suggests that detecting such escapes may be tougher than previously thought.
In 2001, when biologists David Quist and Ignacio Chapela reported finding transgenes from GM corn in traditional varieties in Oaxaca, Mexico, they faced a barrage of criticism over their techniques. Nature , which had published the research, eventually disowned their paper, while a second study by different researchers failed to back up their findings.
But now, Elena Alvarez-Buylla of the National Autonomous University in Mexico City and her team have backed Quist and Chapela's claim. They found transgenes in about 1 per cent of nearly 2000 samples they took from the region (Molecular Ecology , vol 18, p 750).
"They are out there, but it's hit-and-miss," says Paul Gepts of the University of California, Davis, a co-author of the new study. The escaped transgenes are common in a few fields and absent in others, he says, so gene-monitoring efforts must sample as broadly as possible.
What's more, not every detection method - or laboratory - identified every sample containing transgenes. Monitors should use many methods to avoid false negatives, says Gepts.
2.New study points to GM contamination of Mexican corn
AFP, 23 FEB 2009
PARIS Ëœ Genes from genetically-engineered corn have been found in traditional crop strains in Mexico, according to a new study likely to reignite a bitter controversy over biotech maize.
The paper, by scientists from Mexico, the United States and the Netherlands, backs a 2001 probe that sparked a row over the safety of genetically-modified (GM) crops.
Green activists say GM crops are a potential hazard, arguing that their genes could spread to related plants through cross-pollination.
Their campaign has helped drive bans on GM crops in some countries, including Mexico itself, the ancestral home of maize, as corn is also called.
In the 2001 study, published in the prestigious British journal Nature, researchers reported finding transgenes in samples of corn taken from the Sierra Juarez region of Oaxaca.
But this study was blasted for technical inaccuracy and choice of samples. In an exceptional slap, Nature distanced itself from the paper, saying the evidence had not been strong enough to warrant publication.
This damning verdict was underscored by a further study, carried out in 2005 by a different team, that was unable to replicate the results.
But new research now says the original study was right.
A team led by Elena Alvarez-Buylla of the National Autonomous University in Mexico City looked at nearly 2,000 samples from 100 fields in the region from 2001 and 2004, and found that around one percent of the samples had genes that had jumped from GM varieties.
"We confirmed that there was contamination in 2001 and also found contamination in 2004, which means that it either persisted in the local maize that we sampled or that it was reintroduced, which is less likely," Alvarez-Buylla told AFP.
She said the difference between previous studies and her research lay in the samples chosen for gene sequencing and in the molecular technique for decrypting the DNA.
The investigators looked for two specific genes that had escaped from biotech corn, and found them in some fields but not in others.
Alvarez-Buylla said the evidence shed stark light on the failure of efforts to shield Mexico from unauthorised GM corn.
The country imposed a moratorium on the planting of transgenic maize in 1998 in order to protect genetic diversity. It is the home of about 60 traditional domesticated strains, also called landraces, as well as several wild strains.
Transgenic seeds are entering the country, most probably from the United States, and getting mixed with local seeds in trade among small farmers, Alvarez-Buylla believed.
"It is very hard to avoid gene flow from transgenic maize to non-transgenic maize in Mexico, even though there has been a moratorium," she said.
"It is really worrying that the government of Mexico has not been efficient enough in biosecurity monitoring," she said, accusing watchdogs of failing to establish rigorous molecular monitoring that was independent of data provided by biotech giants.
Alvarez-Buylla's team did not explore the impact of the escaped genes on the native corn, on the local environment or human health, nor did it test whether the foreign genes passed on to progeny plants.
The study appears in the latest issue of Molecular Ecology, a peer-reviewed journal published by Britain's Blackwell group. It has been endorsed by a lead author of the 2005 paper.
GM crops have had genes inserted into them to produce benefits for farmers. For instance, they exude natural toxins that kill off pests, or are resistant to herbicides, enabling a farmer to spray a field in one go and not kill the crop.
GM producers say there is no evidence of any threat to human health or the environment. The overwhelming view of scientists is that, so far, this is true.
But suspicions remain strong in many countries, especially Europe, where several governments retain safeguard measures against GM corn despite EU-wide approval.