Fate of Recombinant DNA and Bt Protein After Ingestion and Dispersal of Wild Boars and Deer

With funding from the German Federal Agency for Nature Conservation, researchers from the Technical University of Munich (TUM) examined in detail how fallow deer (Dama dama) and wild boars (Sus scrofa) metabolize genetically modified corn. Specifically, the scientists wanted to find out if transgenic residues accumulate in boar and deer meat and if the animals spread GM corn via their feces. The answer in each case is no, according to the TUM scientists.

Heinrich Mayer and colleagues fed fallow deer living in outdoor enclosures and wild boars kept in pens genetically modified corn chaff and grain corn for several weeks in a row. To study the degradability of ingested DNA, they used polymerase chain reaction (PCR) assays to detect fragments of GM-corn specific genes. ELISA was also used to detect the Cry1Ab protein.

Samples from the digestive tract, internal organs, blood and muscles of fallow deer all tested negative for the presence of transgenic components. "In conclusion, after uptake of GM corn, neither cry1Ab-specific gene fragments nor Cry1Ab protein were detected in the GI tract of fallow deer, indicating complete digestion of the GM corn," Mayer and colleagues wrote in the paper published by the European Journal of Wildlife Research. The researchers found small fragments of GM corn genes in the digestive tract of GM-fed wild boars. However, outside of the gastrointestinal tract the scientists found no trace whatsoever.

Mayer and his team also collected samples of feces for intact kernels capable of germination. They reported that for wild boars a mere 0.015 percent of the conventional and 0.009 percent of the GM corn kernels were excreted intact. The fallow deer were even tougher on the corn: Not a single intact and thus germinable corn could be found in their feces.

The papers published by the European Journal of Wildlife Research and Mammalian Biology are available for download at http://dx.doi.org/10.1007/s10344-007-0104-4 and http://dx.doi.org/10.1016/j.mambio.2008.07.002 respectively.