Effect Measure

Apparent spread of transgenes from GM corn

In 2001 Ignacio Chapela, an ecologist from the University of California, Berkeley, and co-author David Quist published a highly controversial paper in Nature that appeared to show that genetically engineered genes used in genetically modified (GM) corn (maize) was spreading from GM cornfields in Mexico into traditional corn crops. This set off a firestorm where proponents of GM agriculture declared the paper fatally flawed, pointing out some apparent errors. Accusations of agribusiness conflicts of interest were traded with those of political agendas. Nature subsequently published an “editor’s note” stating the journal felt the paper’s data were insufficient to support its conclusions. The journal has been careful to say that the editor’s note was not the same as a retraction, although advocates of GM crops have claimed it was. A subsequent paper in Proceedings of the National Academy of Sciences (PNAS) by Ohio State plant ecologist Allison Snow failed to find transgenes in maize in the same areas sampled by Chapela and Quist, although questions about that paper were raised on the grounds of statistical power. Now the latest chapter, a forthcoming paper in the journal Molecular Ecology by yet another researcher, Elena Álvarez-Buylla of the National Autonomous University of Mexico (UNAM) in Mexico City:

Transgenes from genetically modified (GM) maize (corn) crops have been found in traditional ‘landrace’ maize in the Mexican heartland, a study says. The work largely confirms a similar, controversial result published in Nature in 2001 and may reignite the debate in Mexico over GM crops.

The paper reports finding transgenes in three of the 23 locations that were sampled in 2001, and again in two of those locations using samples taken in 2004.

[snip]

In 1998, the Mexican government outlawed the planting of GM maize to protect its approximately 60 domesticated landraces and their wild relatives. But newspaper reports suggest that farmers have planted at least 70 hectares of GM maize crops in the northern state of Chihuahua, and it is unclear what repercussions this may have.

Only about 25% of the maize planted in Mexico comes from commercially sold seed; the majority is saved from harvest to harvest. That’s why, says Álvarez-Buylla, researchers need to pin down whether transgenes really have made it into local crops. “It is urgent to establish rigorous molecular and sampling criteria for biomonitoring at centres of crop origination and diversification,” the team writes. (Rex Dalton, Nature News)

The new paper examined thousands of seed and leaf samples, looking for the presence of two genes introduced into GM crops, a gene promoter from the 35S cauliflower mosaic virus, and the nopaline synthase terminator, NOSt. They found them in about 1 in 100 fields. These included fields sampled by Chapela and Quist in the 2001 paper. Snow, the author of the PNAS paper that didn’t confirm the Chapela findings, said she believes the new Nature paper is well done and significant for showing how easily the transgene have spread.

The controversy is far from over. The paper was submitted to PNAS but rejected as of insufficient interest, noting in addition the opinion of a reviewer that it could, according to the story in Nature, “gain undue exposure in the press due to a political or other environmental agenda.” That was a reviewer’s comment, not the editor’s view, but one wonders what role that notion played in the decision of PNAS not to publish this paper. It is interesting to observe that PNAS published the Snow paper with negative results, declined to publish the Álvarez-Buylla paper with positive results, while Nature published the Chapela paper in 2001, appeared to have gotten its fingers singed in the ensuing brouhaha, and is now running a news piece about a yet to be published paper in another journal that seems to confirm their earlier publication.

No pride or politics involved, though. That’s for sure.

Comments

  1. #1 brc
    November 18, 2008

    nice catch. thanks for this summary. ben

  2. #2 phisrow
    November 18, 2008

    I’m guessing that the evidence will start to look much more conclusive when we get to the “Monsanto shaking down everybody who might possibly have ever grown something that contained one of their precious copyrighted genes” phase.

    I am in much closer touch with the stuff involving computers; but the fact that having your crop infected by somebody else’s modified one is grounds for legal harassment has got to be the most unjust part of IP law.

  3. #3 Sandra Porter
    November 18, 2008

    Revere:

    Cauliflower mosaic virus is a plant virus and the nopaline synthetase gene in question, is from Agrobacterium tumefaciens, a type of bacteria that lives on plants, in plants, and in soil.

    Yes, those genes are used in transgenic plants, too. But how do you know that the genes that were identified originated from the transgenic plants and not from the environment?

  4. #4 Nomen Nescio
    November 19, 2008

    Yes, those genes are used in transgenic plants, too. But how do you know that the genes that were identified originated from the transgenic plants and not from the environment?

    you probably don’t, but Monsanto will be more than happy to sue you for infringing on their copyrighted genes regardless.

  5. #5 Gindy
    November 19, 2008

    As Nomen states, YOU might not know but Monsanto will. You can bet your bottom dollar there is some sort of unique marker on those genes and if it shows up in those places it isn’t supposed to, Monsanto will make sure they get their cut.
    It happens here in the USA and it will happen there.

  6. #6 ipmat
    November 19, 2008

    I’m sure I’m missing something here, but why can’t the affected farmer(s) sue Monsanto for contaminating the fields? Is it just a difference in the level of lawyer each side can afford?

    I’d think this would be a *serious* problem anywhere the farmers were trying for organic certificaton. Organic fans do NOT like the idea of eating transgenic plants!

  7. #7 caia
    November 19, 2008

    phisrow — that phase is already here. Monsanto famously sued Percy Schmeiser after their GM canola contaminated his fields.

  8. #8 Jonathon Singleton
    November 20, 2008

    Thanks Caia, for reminding me ’bout the traumatizing Percy Schmeiser and Monsanto debacle. I was studying at college at that time telling amused lecturers ’bout the probability of some new cross-species disease emerging. Well, here we all are in 2008:*) watching human H5N1 affect international tourism into Indonesia!?!

  9. #9 otbricki
    September 20, 2010

    Oh no, not Percy again. He got sued for selecting for RoundUp resistance by spraying a part of his land with RoundUp and then reusing the seed. When investigate it was found his crop had 95% RoundUp resistance.

    This was an intentional reuse for commercial advantage.