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MIR604 is a variety of Bt Corn made by Syngenta. It was deregulated in the U.S. in 2007 and commercialized by Syngenta under the brand name "Agrisure® RW."[1] MIR604 is corn that has been genetically engineered to produce an insecticidal protein that is naturally made by a bacteria called Bacillus thuringiensis (Bt), in every cell of the plant. It is marketed as corn rootworm resistant. Bt crops and genetically modified organisms are controversial throughout the world.


On December 24, 2004, Syngenta petitioned the USDA's Animal and Plant Health Inspection Service (APHIS) to deregulate MIR604. APHIS asked for more information and Syngenta filed a revised petition on August 2, 2006. APHIS published a notice in the Federal Register on January 10, 2007, soliciting public comments, which were due by February 9, 2007. APHIS performed an Environmental Assessment under the National Environmental Policy Act and concluded a "finding of no significant impact" (FONSI). MIR604 was deregulated in the U.S. on March 16, 2007.

APHIS wrote in the Federal Register:

"Corn transformation event MIR604 has been genetically engineered to express two transgenes: (1) The modified cry3A (mcry3A) gene derived from a well-characterized gene sequence from Bacillus thuringiensis, encoding the mCRY3A insect control protein and (2) the pmi(manA) gene from Eschericha coli, which encodes the enzyme phosphomannose isomerase (PMI) for use as a selectable marker. Expression of the mcry3A gene by corn plants renders the corn lines resistant to CRW [corn rootworm].
"Regulatory elements for the mcry3A and pmi genes were derived from maize and Agrobacterium tumefaciens. These regulatory sequences are not transcribed and do not encode proteins. The DNA was introduced into the corn cells using Agrobacterium-mediated transformation methodology with the T-DNA transformation vector designated pZM26. In addition to transgenes necessary for insertion into the plant genome, the T-DNA vector also contained two additional genetic elements: (1) A gene conferring bacterial resistance to the antibiotics erythromycin, streptomycin, and spectinomycin and (2) the bacterial origin of replication. Plant cells containing the introduced DNA were then selected by culturing in the presence of mannose. After the initial incubation with Agrobacterium, the broad-spectrum antibiotic cefotaxime was included in the culture medium to kill any remaining Agrobacterium."[2]


Syngenta sells MIR604 in the following products:[3]

  • Agrisure® RW
  • GT/RW (MIR604 and SYTGA21)
  • Agrisure® CB/LL/RW (Bt11 and MIR604)
  • Agrisure® 3000GT (Bt11, SYTGA21, and MIR604)

Articles and resources

Related SourceWatch articles


  1. A Compendium of Corn Biotech Traits, Purdue University, Accessed August 12, 2012.
  2. Federal Register, Vol. 72, No. 56, March 23, 2007.
  3. A Compendium of Corn Biotech Traits, Purdue University, Accessed August 12, 2012.

External resources

External articles