A decade-long project to develop genetically modified peas with built-in pest-resistance has been abandoned after tests showed they caused allergic lung damage in mice.The researchers – at Australia’s national research organisation, CSIRO – took the gene for a protein capable of killing pea weevil pests from the common bean and transferred it into the pea. When extracted from the bean, this protein does not cause an allergic reaction in mice or people. But the team found that when the protein is expressed in the pea, its structure is subtly different to the original in the bean. They think this structural change could be to blame for the unexpected immune effects seen in mice. The work underlines the need to evaluate new GM crops on a case-by-case basis, says Paul Foster of the Australian National University in Canberra, who led the immunological work. He also calls for improvements in screening requirements for genetically engineered plants, to ensure comprehensive tests are carried out. Jeremy Tager, Greenpeace Australia’s campaigner on genetic engineering, agrees. “These results indicate the potential for unpredicted and unintended changes in the structure of transferred proteins. And I’m not aware of any country that requires feeding studies as part of its approval process.”
