Antony Barnett, James Meikle and John Vidal
A zoologist has found evidence that genes used to modify crops can jump the species barrier and cause bacteria to mutate.
A four-year study by Professor Hans- Hinrich Kaatz found that the alien gene used to modify oilseed rape had transferred to bacteria living in the guts of bees. His research poses questions for the biotech industry, which believes the chances of gene transfer between species are limited.
The research, which has yet to be published and has not been reviewed by fellow scientists, suggests that all types of bacteria may become contaminated by genes used in genetically modified (GM) organisms, including bacteria that live inside the human digestive system. If this happened, it could affect the bacteria’s role in helping the human body fight disease, aid digestion and facilitate blood-clotting.
Prof Kaatz, who works at the Institute for Bee Research at the University of Jena in Germany, has been experimenting with honey bees on a field sown with GM oilseed rape, engineered to resist certain herbicides.
He removed pollen gathered by the bees on their hind legs when they returned to the hive, and fed it to young bees. Then he took out their intestines. In some bacteria and in a yeast from the gut he found the gene that conferred resistance to the herbicide.
“This happened rarely, but it did happen,” Prof Kaatz said. British agriculture minister, Nick Brown, said: “If this is true, then it would be very serious.”
Dr Mae-Wan Ho, a geneticist at Britain’s Open University, said: “These findings are very worrying and provide the first real evidence of what many have feared. Everybody is keen to exploit GM technology, but nobody is looking at the risk of horizontal gene transfer.”
One of the biggest concerns is if the antibiotic-resistant gene used in some genetically modified crops crossed over to bacteria.
“If this happened it would leave us unable to treat major illnesses like meningitis and E. coli,” Dr Ho said.
Meanwhile, international seed suppliers and scientists have admitted that contamination of crops by genetic modification is probably widespread. An article in a recent edition of New Scientist reported on the low-level contamination of seeds sold to Europe.
“In 1998 the UK [United Kingdom] imported 491E000 tonnes of soya beans from North America. If 1% was GM, roughly 5E000 tonnes of GM soya beans were imported,” the magazine said.
Pioneer Hi-Bred, the world’s largest supplier of GM and conventional seeds, acknowledged that a low level of mingling between the types was inevitable.
Garlich von Essen, a representative for the European Seed Association, said there were one or two incidents last year when conventional maize had been found to be contaminated with GM seed. “Everyone knew about it,” he said. “There was no legal provision for this, so French growers guaranteed there was not more than 1%. The guarantee does not mean there is GM, but it guarantees there is not more than 1%.”
Scientists in the US said there was “widespread” contamination of all conventional seeds. “It’s across the board,” said Cheryl Ryan of Genetic-ID, a private firm that screens agricultural produce for GM contamination. “… up to 50% of the seeds we test can be contaminated.”
Last month it was reported that thousands of acres of crops tainted by GM pollen have been growing in Britain for the past two years. Some farmers have already begun ripping up their contaminated crops, or are preparing to do so.