c qualities for yield, harvestability and disease resistance. Three primary components of the genetic package inserted into corn; protein genes, promoters, and genetic markers. Protein genes, Bt genes modified for improved expression in corn, produce Cry proteins. Initial Bt hybrids in the United States and Canada includes one of three Cry proteins, Cry1Ab, Cry1Ac or Cry9C. Future hybrids may produce other Cry proteins, or proteins from other sources. A promoter controls where and how much of the Cry protein a plant produces. Some promoters limit protein production to specific parts of the plant (for example, leaves, green tissue and pollen) whereas others produce protein throughout the plant. The presence of a genetic marker allows seed companies to identify successful transformations. Current examples of markers include genes for herbicide resistance or antibiotic resistance....
