MADISON -- Working with teosinte, a wild cousin of maize, a University of Wisconsin-Madison scientist has found a molecular barrier that, bred into modern hybrid corn, is capable of completely locking out foreign genes, including those from genetically modified corn.
The discovery is important because it means farmers will have access to a technology that can ensure the genetic integrity of their corn crop, making it easier to export to countries wary of recombinant DNA technology and providing a built-in buffer for potential environmental problems such as the threat to monarch butterflies from corn engineered to make its own biological insecticides.
"Governing the flow of genes between populations is what's at stake," says Jerry L. Kermicle, the UW-Madison professor of genetics who discovered teosinte's genetic barrier.
Corn varieties of all kinds -- from organic to genetically engineered -- are prolific traffickers in genes. Cross-fertilization between strains occurs as gene-laden pollen is carried by bees or blown with the wind from one field to another. The resulting contamination, especially from genetically modified corn, can ruin organic crops or make traditional hybrid corn worthless for export to countries where consumers are wary of the new technology.
The new discovery, however, could permit American farmers to recapture those profitable markets in Europe and Asia by ensuring that organic or traditional hybrid corn is uncontaminated by genes from genetically modified crops.
Moreover, the new technology can be used by farmers to plant buffers around fields of corn genetically modified to make their own insecticides and thereby limiting a highly-publicized threat to non-target species such as monarch butterflies.
For thousands of years, teosinte has co-existed as a weed with the maize cultivated in Mexican fields. Like corn, teosinte is a grass and its genetic makeup is so similar to that of cultivated maize that scientists susp
Contact: Jerry L. Kermicle
University of Wisconsin-Madison