Occurrence of the Transgenic Corn cry1Ab Gene in Freshwater Mussels (Elliptio Complanata) Near Corn Fields: Evidence of Exposure by Bacterial Ingestion

Ecotoxicol Environ Saf. 2009 Jan;72(1):17-25. doi: 10.1016/j.ecoenv.2008.02.006. Epub 2008 Apr 7.


The purpose of this study was to examine the contamination of cry1 and cry1Ab genes from Bacillus thuringiensis and transgenic corn in feral freshwater mussels collected from sites located in proximity of corn fields. In addition, mussels were transplanted for 2 months to a site in the Huron River, upstream to the Richelieu River, which is subject to intensive corn farming. Mussels were significantly contaminated by both genes in their gills, digestive glands, and gonads, as determined by qPCR methodology. Gene sequence analysis confirmed the presence of transgenic corn cry1Ab gene in mussel tissues. In an attempt to explain the presence of the transgene in mussel tissues, heterotrophic bacteria were grown from surface water and sediment samples on agar plates in the Richelieu River in May and August. The transgene was found at two out of six surface water samples and in one sediment sample. The study revealed that exposure to transgenic corn cry1Ab gene in mussels seems to proceed by ingestion of microorganisms during feeding.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animal Feed
  • Animals
  • Animals, Wild
  • Bacillus thuringiensis / genetics
  • Bacterial Proteins / genetics*
  • Bacterial Proteins / toxicity
  • Bivalvia / genetics
  • Bivalvia / physiology*
  • Coleoptera / drug effects
  • Coleoptera / genetics
  • Culicidae / drug effects
  • Culicidae / genetics
  • Diptera / drug effects
  • Diptera / genetics
  • Ecosystem
  • Endotoxins / genetics*
  • Endotoxins / toxicity
  • Fresh Water
  • Hemolysin Proteins / genetics*
  • Hemolysin Proteins / toxicity
  • Humans
  • Insect Control / methods
  • Ontario
  • Plants, Genetically Modified* / genetics
  • Quebec
  • Zea mays / genetics*
  • Zea mays / microbiology


  • Bacterial Proteins
  • Endotoxins
  • Hemolysin Proteins
  • insecticidal crystal protein, Bacillus Thuringiensis