Genetically modified maize
Genetically modified maize (corn) is a genetically modified plant. Specific maize strains have been genetically engineered to express agriculturally-desirable traits, including resistance to pests and to herbicides. Maize strains with both traits are now in use in multiple countries. GM maize has also caused controversy with respect to possible health effects, impact on other insects and impact on other plants via gene flow. One strain, called Starlink, was approved only for animal feed in the US, but was found in food, leading to a series of recalls starting in 2000.
Herbicide resistant maize
Corn varieties resistant to glyphosate herbicides were first commercialized in 1996 by Monsanto, and are known as "Roundup Ready Corn". They tolerate the use of Roundup. Bayer CropScience developed "Liberty Link Corn" that is resistant to glufosinate. Pioneer Hi-Bred has developed and markets corn hybrids with tolerance to imidazoline herbicides under the trademark "Clearfield" - though in these hybrids, the herbicide-tolerance trait was bred using tissue culture selection and the chemical mutagen ethyl methanesulfonate not genetic engineering. Consequently, the regulatory framework governing the approval of transgenic crops does not apply for Clearfield.
As of 2011, herbicide-resistant GM corn was grown in 14 countries. By 2012, 26 varieties herbicide-resistant GM maize were authorised for import into the European Union. In 2012 the EU was reported to import 30 million tons a year of GM crops, but such imports remain controversial. Cultivation of herbicide-resistant corn in the EU provides substantial farm-level benefits.
Bt corn is a variant of maize that has been genetically altered to express one or more proteins from the Bacillus thuringiensis bacteria. The protein is poisonous to certain insect pests and is widely used in organic gardening. The European corn borer causes about a billion dollars in damage to corn crops each year.
The Bt protein is expressed throughout the plant. When a vulnerable insect eats the Bt-containing plant, the protein is activated in its gut, which is alkaline (human guts are acidic). In the alkaline environment the protein partially unfolds and is cut by other proteins, forming a toxin that paralyzes the insect's digestive system and forms holes in the gut wall. The insect stops eating within a few hours and eventually starves.
In 1996, the first GM maize producing a Bt Cry protein was approved, which killed the European corn borer and related species; subsequent Bt genes were introduced that killed corn rootworm larvae.
Bt genes that are approved include the following, singly and stacked (event name between brackets): Cry1A.105 (MON89034), CryIAb (MON810), CryIF (1507), Cry2Ab (MON89034), Cry3Bb1 (MON863 and MON88017), Cry34Ab1 (59122), Cry35Ab1 (59122), mCry3A (MIR604), and Vip3A (MIR162), in both corn and cotton.:285ff Corn genetically modified to produce VIP was first approved in the US in 2010.
Products in development
The theory behind these refuges is to slow the evolution of resistance to the pesticide. EPA regulations also require seed companies to train farmers how to maintain refuges, to collect data on the refuges and to report that data to the EPA. A study of these reports found that from 2003 to 2005 farmer compliance with keeping refuges was above 90%, but that by 2008 approximately 25% of Bt corn farmers did not keep refuges properly, raising concerns that resistance would develop.
Unmodified crops received most of the economic benefits of Bt corn in the US in 1996-2007, because of the overall reduction of pest populations. This reduction came because females laid eggs on modified and unmodified strains alike.
In November 2009, Monsanto scientists found the pink bollworm had become resistant to first-generation Bt cotton in parts of Gujarat, India - that generation expresses one Bt gene, Cry1Ac. This was the first instance of Bt resistance confirmed by Monsanto anywhere in the world. Bollworm resistance to first generation Bt cotton has been identified in the Australia, China, Spain and the United States. In 2012, a Florida field trial demonstrated that army worms were resistant to pesticide-containing GM corn produced by Dupont-Dow; armyworm resistance was first discovered in Puerto Rico in 2006, prompting Dow and DuPont to voluntarily stop selling the product on the island.
Regulation of GM crops varies between countries, with some of the most-marked differences occurring between the USA and Europe. Regulation varies in a given country depending on intended uses.
Broad scientific consensus holds that food derived from GM crops poses no greater risk to human health than conventional food. GM crops also provide a number of ecological benefits.
Critics have objected to GM crops on ecological, economic and health grounds.
The economic issues derive from those organisms that are subject to intellectual property law, mostly patents. The first generation of GM crops lose patent protection beginning in 2015. Monsanto has committed not to pursue farmers who retain seeds of off-patent varieties.
Effects on nontarget insects
Critics claim that Bt proteins could target predatory and other beneficial or harmless insects as well as the targeted pest. These proteins have been used as organic sprays for insect control in France since 1938 and the USA since 1958 with no ill effects on the environment reported. While cyt proteins are toxic towards the insect orders Coleoptera (beetles) and Diptera (flies), cry proteins selectively target Lepidopterans (moths and butterflies). As a toxic mechanism, cry proteins bind to specific receptors on the membranes of mid-gut (epithelial) cells, resulting in rupture of those cells. Any organism that lacks the appropriate gut receptors cannot be affected by the cry protein, and therefore Bt. Regulatory agencies assess the potential for the transgenic plant to impact nontarget organisms before approving commercial release.
A 1999 study found that in a lab environment, pollen from Bt maize dusted onto milkweed could harm the monarch butterfly. Several groups later studied the phenomenon in both the field and the laboratory, resulting in a risk assessment that concluded that any risk posed by the corn to butterfly populations under real-world conditions was negligible. A 2002 review of the scientific literature concluded that "the commercial large-scale cultivation of current Bt–maize hybrids did not pose a significant risk to the monarch population". A 2007 review found that "nontarget invertebrates are generally more abundant in Bt cotton and Bt maize fields than in nontransgenic fields managed with insecticides. However, in comparison with insecticide-free control fields, certain nontarget taxa are less abundant in Bt fields."
Gene flow is the transfer of genes and/or alleles from one species to another. Concerns focus on the interaction between GM and other maize varieties in Mexico, and of gene flow into refuges.
In 2009 the government of Mexico created a regulatory pathway for genetically modified maize, but because Mexico is the center of diversity for maize, gene flow could affect a large fraction of the world's maize strains. A 2001 report in Nature presented evidence that Bt maize was cross-breeding with unmodified maize in Mexico. The data in this paper was later described as originating from an artifact. Nature later stated, "the evidence available is not sufficient to justify the publication of the original paper". A 2005 large-scale study failed to find any evidence of contamination in Oaxaca. However, other authors also found evidence of cross-breeding between natural maize and transgenic maize.
A 2004 study found Bt protein in kernels of refuge corn.
The French High Council of Biotechnologies Scientific Committee reviewed the 2009 Vendômois et al. study and concluded that it "..presents no admissible scientific element likely to ascribe any haematological, hepatic or renal toxicity to the three re-analysed GMOs." However, the French government applies the precautionary principle with respect to GMOs.
A 2011 Canadian study looked at the presence of CryAb1 protein (BT toxin) in non-pregnant women, pregnant women and fetal blood. All groups had detectable levels of the protein, including 93% of pregnant women and 80% of fetuses at concentrations of 0.19 ± 0.30 and 0.04 ± 0.04 mean ± SD ng/ml, respectively. The paper did not discuss safety implications or find any health problems. The paper was found to be unconvincing by multiple authors and organizations. In a swine model, Cry1Ab-specific antibodies were not detected in pregnant sows or their offspring and no negative effects from feeding Bt maize to pregnant sows were observed.
StarLink contains Cry9C, which had not previously been used in a GM crop. Starlink's creator, Plant Genetic Systems had applied to the US Environmental Protection Agency (EPA) to market Starlink for use in animal feed and in human food.:14 However, because the Cry9C protein lasts longer in the digestive system than other Bt proteins, the EPA had concerns about its allergenicity, and PGS did not provide sufficient data to prove that Cry9C was not allergenic.:3 As a result PGS split its application into separate permits for use in food and use in animal feed. Starlink was approved by the EPA for use in animal feed only in May 1998.:15
StarLink corn was subsequently found in food destined for consumption by humans in the US, Japan, and South Korea.:20–21 This corn became the subject of the widely publicized Starlink corn recall, which started when Taco Bell-branded taco shells sold in supermarkets were found to contain the corn. Sales of StarLink seed were discontinued. The registration for Starlink varieties was voluntarily withdrawn by Aventis in October 2000. (Pioneer had been bought by AgrEvo which then became Aventis CropScience at the time of the incident,:15–16 which was later bought by Bayer
Fifty-one people reported adverse effects to the FDA; US Centers for Disease Control (CDC), which determined that 28 of them were possibly related to Starlink. However, the CDC studied the blood of these 28 individuals and concluded there was no evidence of hypersensitivity to the Starlink Bt protein.
A subsequent review of these tests by the Federal Insecticide, Fungicide, and Rodenticide Act Scientific Advisory Panel points out that while "the negative results decrease the probability that the Cry9C protein is the cause of allergic symptoms in the individuals examined ... in the absence of a positive control and questions regarding the sensitivity and specificity of the assay, it is not possible to assign a negative predictive value to this."
The US corn supply has been monitored for the presence of the Starlink Bt proteins since 2001.
In 2005, aid sent by the UN and the US to Central American nations also contained some StarLink corn. The nations involved, Nicaragua, Honduras, El Salvador and Guatemala refused to accept the aid.
- "Roundup Ready System". Monsanto.
- Bayer LibertyLink official website
- Tan, S.; Evans, R. R.; Dahmer, M. L.; Singh, B. K.; Shaner, D. L. (2005). "Imidazolinone-tolerant crops: History, current status and future". Pest Management Science 61 (3): 246–257. doi:10.1002/ps.993. PMID 15627242.
- James, C (2011). "ISAAA Brief 43, Global Status of Commercialized Biotech/GM Crops: 2011". ISAAA Briefs. Ithaca, New York: International Service for the Acquisition of Agri-biotech Applications (ISAAA). Retrieved 2012-07-27.
- Staff EU register of genetically modified food and feed European Commission, Health and Consumers, EU register of authorised GMOs, Retrieved 26 August 2012
- Hogan, Michael (5 April 2012) BASF to undertake GMO potato trials in Europe Reuters Edition US, Accessed 26 August 2012
- Wesseler, J., S. Scatasta, E. Nillesen (2007): The Maximum Incremental Social Tolerable Irreversible Costs (MISTICs) and other Benefits and Costs of Introducing Transgenic Maize in the EU-15. Pedobiologia 51(3):261-269
- "History of Bt". University of California. Retrieved 8 February 2010.
- Ostlie KR et al. University of Minnesota Extension Office. Last Reviewed 2008. Bt Corn & European Corn Borer: Long-Term Success Through Resistance Management
- Marra, M.C., Piggott, N.E., & Goodwin, B.K. (2012). The impact of corn rootworm protected biotechnology traits in the United States. AgBioForum, 15(2), 217-230
- Erin W. Hodgson, Utah State University Extension and Utah Plant Pest Diagnostic Laboratory. Western corn rootworm
- W.S. Cranshaw, Colorado State University Extension Office. Last updated March 26, 2013. Bacillus thuringiensis Fact Sheet
- Hellmich, R. L. & Hellmich, K. A. (2012) Use and Impact of Bt Maize. Nature Education Knowledge 3(10):4
- Ric Bessin, Extension Entomologist, University of Kentucky College of Agriculture. May 1996, last updated November 2010. Bt-Corn for Corn Borer Control
- Castagnola AS, Jurat-Fuentes, JL. Bt Crops: Past and Future. Chapter 15 in [Bacillus Thuringiensis Biotechnology], Ed. Estibaliz Sansinenea. Springer, Mar 2, 2012
- Erin Hodgson and Aaron Gassmann, Iowa State Extension, Department of Entomology. May 2010. [New Corn Trait Deregulated in U.S. http://www.extension.iastate.edu/CropNews/2010/0510hodgsongassman.htm]
- Staff, Monsanto. August, 2009. Application for authorization to place on the market MON 87701 × MON 89788 soybean in the European Union, according to Regulation (EC) No 1829/2003 on genetically modified food and feed Linked from the GMO Compass page on the MON87701 x MON89788 event.
- Monsanto's Bt Roundup Ready 2 Yield Soybeans Approved for Planting in Brazil - Crop Biotech Update (8/27/2010) | ISAAA.org/KC
- Syngenta Sweet Corn Products
- Shepherd DN, Mangwende T, Martin DP, et al. (November 2007). "Maize streak virus-resistant transgenic maize: a first for Africa". Plant Biotechnol. J. 5 (6): 759–67. doi:10.1111/j.1467-7652.2007.00279.x. PMID 17924935.
- J.F. Witkowski; J.L. Wedberg, K.L. Steffey, P.E., et al. (2002). Bt Corn & European Corn Borer: Long-Term Success Through Resistance Management (Report). University of Minnesota. http://www.extension.umn.edu/distribution/cropsystems/dc7055.html#ch11.
- Tabashnik, B. E. (2010). "Communal Benefits of Transgenic Corn". Science 330 (6001): 189–190. doi:10.1126/science.1196864. PMID 20929767.
- Staff, University of Minnesota Extension. Section: Can European corn borer develop resistance to Bt corn? in the Bt Corn & European Corn Borer
- "Cotton in India". Monsanto. 5 May 2010.
- Bagla P (March 2010). "India. Hardy cotton-munching pests are latest blow to GM crops". Science 327 (5972): 1439. Bibcode:2010Sci...327.1439B. doi:10.1126/science.327.5972.1439. PMID 20299559.
- Tabashnik BE, Gassmann AJ, Crowder DW, Carriére Y (February 2008). "Insect resistance to Bt crops: evidence versus theory". Nat. Biotechnol. 26 (2): 199–202. doi:10.1038/nbt1382. PMID 18259177.
- Jack Kaskey for Bloomberg News Nov 16, 2012 DuPont-Dow Corn Defeated by Armyworms in Florida: Study
- Wesseler, J. and N. Kalaitzandonakes (2011): Present and Future EU GMO policy. In Arie Oskam, Gerrit Meesters and Huib Silvis (eds.), EU Policy for Agriculture, Food and Rural Areas. Second Edition, pp. 23-323 – 23-332. Wageningen: Wageningen Academic Publishers
- Beckmann, V., C. Soregaroli, J. Wesseler (2011): Coexistence of genetically modified (GM) and non-modified (non GM) crops: Are the two main property rights regimes equivalent with respect to the coexistence value? In "Genetically modified food and global welfare" edited by Colin Carter, GianCarlo Moschini and Ian Sheldon, pp 201-224. Volume 10 in Frontiers of Economics and Globalization Series. Bingley, UK: Emerald Group Publishing
- American Association for the Advancement of Science (AAAS), Board of Directors (2012). Legally Mandating GM Food Labels Could Mislead and Falsely Alarm Consumers
- A decade of EU-funded GMO research (2001-2010) (PDF). Directorate-General for Research and Innovation. Biotechnologies, Agriculture, Food. European Union. 2010. doi:10.2777/97784. ISBN 978-92-79-16344-9. ""The main conclusion to be drawn from the efforts of more than 130 research projects, covering a period of more than 25 years of research, and involving more than 500 independent research groups, is that biotechnology, and in particular GMOs, are not per se more risky than e.g. conventional plant breeding technologies." (p. 16)"
- Ronald, Pamela (2011). "Plant Genetics, Sustainable Agriculture and Global Food Security". Genetics 188 (1): 11–20.
- American Medical Association (2012). Report 2 of the Council on Science and Public Health: Labeling of Bioengineered Foods
- FAO, 2004. State of Food and Agriculture 2003–2004. Agricultural Biotechnology: Meeting the Needs of the Poor. Food and Agriculture Organization of the United Nations, Rome. "Currently available transgenic crops and foods derived from them have been judged safe to eat and the methods used to test their safety have been deemed appropriate. These conclusions represent the consensus of the scientific evidence surveyed by the ICSU (2003) and they are consistent with the views of the World Health Organization (WHO, 2002). These foods have been assessed for increased risks to human health by several national regulatory authorities (inter alia, Argentina, Brazil, Canada, China, the United Kingdom and the United States) using their national food safety procedures (ICSU). To date no verifiable untoward toxic or nutritionally deleterious effects resulting from the consumption of foods derived from genetically modified crops have been discovered anywhere in the world (GM Science Review Panel). Many millions of people have consumed foods derived from GM plants - mainly maize, soybean and oilseed rape - without any observed adverse effects (ICSU)."
- Other sources:
- World Health Organization. Food safety: 20 questions on genetically modified foods. Accessed December 22, 2012.
- United States Institute of Medicine and National Research Council (2004). Safety of Genetically Engineered Foods: Approaches to Assessing Unintended Health Effects. National Academies Press. Free full-text. National Academies Press. See pp11ff on need for better standards and tools to evaluate GM food.
- Tamar Haspel for the Washington Post. October 15, 2013. Genetically modified foods: What is and isn’t true
- Winter CK and Gallegos LK (2006). Safety of Genetically Engineered Food. University of California Agriculture and Natural Resources Communications, Publication 8180.
- Miller, Henry (2009). "A golden opportunity, squandered". Trends in Biotechnology 27 (3): 129–130.
- Dr. Christopher Preston, AgBioWorld 2011. Peer Reviewed Publications on the Safety of GM Foods.
- Andrew Pollack for the New York Times. April 13, 2010 Study Says Overuse Threatens Gains From Modified Crops
- ANDREW POLLACK (December 17, 2009). "As Patent Ends, a Seed’s Use Will Survive". New York Times. Retrieved December 2013.
- Wesseler, J. (ed.) (2005): Environmental Costs and Benefits of Transgenic Crops. Dordrecht, NL: Springer Press
- Hall, H. "Bt corn: is it worth the risk?". The Science Creative Quarterly.
- Dorsch, J.A. et al. Cry1a Toxins of Bacillus Thuringiensis Bind Specifically to a Region Adjacent to the Membrane-Proximal Extracellular Domain of Bt-R-1 in Manduca Sexta: Involvement of a Cadherin in the Entomopathogenicity of Bacillus Thuringiensis. Insect Biochemistry and Molecular Biology 32, 1025-1036 (2002)
- Romeis, J. R.; Hellmich, R. L.; Candolfi, M. P.; Carstens, K.; De Schrijver, A.; Gatehouse, A. M. R.; Herman, R. A.; Huesing, J. E.; McLean, M. A.; Raybould, A.; Shelton, A. M.; Waggoner, A. (2010). "Recommendations for the design of laboratory studies on non-target arthropods for risk assessment of genetically engineered plants". Transgenic Research 20 (1): 1–22. doi:10.1007/s11248-010-9446-x. PMC 3018611. PMID 20938806.
- Romeis, J. R.; Bartsch, D.; Bigler, F.; Candolfi, M. P.; Gielkens, M. M. C.; Hartley, S. E.; Hellmich, R. L.; Huesing, J. E.; Jepson, P. C.; Layton, R.; Quemada, H.; Raybould, A.; Rose, R. I.; Schiemann, J.; Sears, M. K.; Shelton, A. M.; Sweet, J.; Vaituzis, Z.; Wolt, J. D. (2008). "Assessment of risk of insect-resistant transgenic crops to nontarget arthropods". Nature Biotechnology 26 (2): 203–208. doi:10.1038/nbt1381. PMID 18259178.
- Losey JE et al. (1999) Transgenic pollen harms monarch larvae. Nature 399: 214
- "Engineered corn kills monarch butterflies". Cornell News. May 19, 1999.
- Sears MK, Hellmich RL, Stanley-Horn DE, Oberhauser KS, Pleasants JM, Mattila HR, Siegfried BD, Dively GP (October 2001). "Impact of Bt corn pollen on monarch butterfly populations: a risk assessment". Proc. Natl. Acad. Sci. U.S.A. 98 (21): 11937–42. Bibcode:2001PNAS...9811937S. doi:10.1073/pnas.211329998. JSTOR 3056827. PMC 59819. PMID 11559842.
- Gatehouse AM, Ferry N, Raemaekers RJ (May 2002). "The case of the monarch butterfly: a verdict is returned". Trends Genet. 18 (5): 249–51. doi:10.1016/S0168-9525(02)02664-1. PMID 12047949.
- "Monarch butterflies: A threat to individual caterpillars, but not to the population as a whole". GMO Safety. Dec 2004.
- "Butterflies and Bt Corn". United States Department of Agriculture. Retrieved June 19, 2005.
- Marvier, M., C. McCreedy, J. Regetz, and P. Kareiva (2007). "A Meta-Analysis of Effects of Bt Cotton and Maize on Nontarget Invertebrates". Science 316 (5830): 1475–1477. Bibcode:2007Sci...316.1475M. doi:10.1126/science.1139208. PMID 17556584.
- GMO Compass. 5 June 2009 Mexico: controlled cultivation of genetically modified maize
- Mike Shanahan for Science and Development Network, 10 November 2004. Warning issued on GM maize imported to Mexico - SciDev.Net
- Katie Mantell for Science and Development Network, 30 November 2001 GM maize found ‘contaminating’ wild strains - SciDev.Net
- Quist D, Chapela IH (November 2001). "Transgenic DNA introgressed into traditional maize landraces in Oaxaca, Mexico". Nature 414 (6863): 541–3. doi:10.1038/35107068. PMID 11734853.
- Kaplinsky N, Braun D, Lisch D, Hay A, Hake S, Freeling M (April 2002). "Biodiversity (Communications arising): maize transgene results in Mexico are artefacts". Nature 416 (6881): 601–2; discussion 600, 602. Bibcode:2002Natur.416..601K. doi:10.1038/nature739. PMID 11935145.
- Ortiz-Garcia, S. (2005). "Absence of detectable transgenes in local landraces of maize in Oaxaca, Mexico (2003-2004)". Proceedings of the National Academy of Sciences 102 (35): 12338. Bibcode:2005PNAS..10212338O. doi:10.1073/pnas.0503356102. PMC 1184035. PMID 16093316.
- Piñeyro-Nelson A, Van Heerwaarden J, Perales HR, Serratos-Hernández JA, Rangel A, Hufford MB, Gepts P, Garay-Arroyo A, Rivera-Bustamante R, Alvarez-Buylla ER (February 2009). "Transgenes in Mexican maize: molecular evidence and methodological considerations for GMO detection in landrace populations". Mol. Ecol. 18 (4): 750–61. doi:10.1111/j.1365-294X.2008.03993.x. PMC 3001031. PMID 19143938.
- Chilcutt, Charles; Tabashnik, BE. (18 May 2004). "Contamination of refuges by Bacillus thuringiensis toxin genes from transgenic maize.". Proceedings of the National Academy of Science of the United States of America 101 (20): 7526–7529. Bibcode:2004PNAS..101.7526C. doi:10.1073/pnas.0400546101. PMC 419639. PMID 15136739.
- Opinion relating to the deposition of 15 December 2009 by the Member of Parliament, François Grosdidier, as to the conclusions of the study entitled “A comparison of the effects of three GM corn varieties on mammalian health” by J. Spiroux de Vendômois, F. Roullier, D. Cellier and G.E. Séralini, Int. J. Biol. Sci, 2009: 5(7) : 706-726. (Report). High Council of Biotechnologies Scientific Committee. http://www.food.gov.uk/multimedia/pdfs/acnfp9612a2.
- EFSA Minutes of the 55th Plenary Meeting of the Scientific Panel on Genetically Mofified Organisms Held on 27-28 January 2010 IN Parma, Italy, Annex 1, Vendemois et al. 2009 European Food Safety Authority report, Retrieved 27 July 2012
- Doull, J.; D. Gaylor, H.A. Greim, D.P. Lovell, B. Lynch, I.C. Munro (November 2007). "Report of an Expert Panel on the reanalysis by of a 90-day study conducted by Monsanto in support of the safety of a genetically modified corn variety (MON 863)." (PDF). Food and Chemical Toxicology 45 (11): 2073–2085. doi:10.1016/j.fct.2007.08.033. PMID 17900781. Retrieved 2012-07-27. "The Se´ralini et al. reanalysis does not advance any new scientific data to indicate that MON 863 caused adverse effects in the 90-day rat study."
- Aris A, Leblanc S (May 2011). "Maternal and fetal exposure to pesticides associated to genetically modified foods in Eastern Townships of Quebec, Canada". Reprod. Toxicol. 31 (4): 528–33. doi:10.1016/j.reprotox.2011.02.004. PMID 21338670.
- Alain de Weck: Une protéine pesticide OGM (Cry1ab) dans le sang de femmes gravides et de leur fœtus? Un travail bâclé et un scénario catastrophe très probablement inexistant
- "Many Women, no Cry - OGM : environnement, santé et politique" (in English and French). Marcel-kuntz-ogm.over-blog.fr. 2012-01-16. Retrieved 2012-02-07.
- "FSANZ response to study linking Cry1Ab protein in blood to GM foods - Food Standards Australia New Zealand". foodstandards.gov.au. 2011-05-27. Retrieved 2012-02-07.
- Buzoianu, S. G.; Walsh, M. C.; Rea, M. C.; O'Donovan, O.; Gelencsér, E.; Ujhelyi, G.; Szabó, E.; Nagy, A.; Ross, R. P.; Gardiner, G. E.; Lawlor, P. G. (2012). "Effects of Feeding Bt Maize to Sows during Gestation and Lactation on Maternal and Offspring Immunity and Fate of Transgenic Material". In Bravo, Alejandra. PLoS ONE 7 (10): e47851. doi:10.1371/journal.pone.0047851. PMC 3473024. PMID 23091650.
- "EFSA promotes public access to data in transparency initiative" (Press release). European Food Safety Authority. January 14, 2013.
- Michael R. Taylor and Jody S. Tick of Resources for the Future, Pew Initiative on Food and Biotechnology. The StarLink Case: Issues for the Future
- "While EPA had no specific data to indicate that Cry9C was an allergen, the protein expressed in StarLink corn did exhibit certain characteristics (i.e. relative heat stability and extended time to digestion) that were common to known food allergens such as those found in peanuts, eggs, etc. EPA’s concern was that StarLink corn may be a human food allergen and in the absence of more definitive data, EPA has not made a decision whether or not to register the human food use." Staff, EPA. November 2000 Executive Summary: EPA Preliminary Evaluation of Information Contained in the October 25, 2000 Submission from Aventis Cropscience
- Plant Genetic Systems (America) Inc.: PP 7G4921 Federal Register Vol. 62, No. 228, November 26, 1997 pp 63169 bottom of middle column - 63170 right column; see especially p63169 top of right column
- King D, Gordon A. Contaminant found in Taco Bell taco shells. Food safety coalition demands recall (press release), vol 2001. Washington, DC: Friends of the Earth, 2000. Available: http://www.foe.org/act/getacobellpr.html. 3 November 2001.
- "Taco Bell Recalls Shells That Used Bioengineered Corn - Los Angeles Times". Articles.latimes.com. 2012-07-03. Retrieved 2013-12-31.
- Agricultural Biotechnology: Updated Benefit Estimates, Janet E. Carpenter and Leonard )P. Gianessi 2001, National Center for Food and Agricultural Policy
- Staff, EPA review committee. LLP Incidents
- CDC, National Center for Environmental Health. Investigation of Human Health Effects Associated with Potential Exposure to Genetically Modified Corn: A Report to the U.S. Food and Drug Administration from the Centers for Disease Control and Prevention. Atlanta,GA:Centers for Disease Control and Prevention, 2001.
- FIFRA Scientific Advisory Panel Report No. 2001-09, July 2001
- "Starlink Corn Regulatory Information". Environmental Protection Agency (EPA). April 2008.
- "Banned as Human Food, StarLink Corn Found in Food Aid". Ens-newswire.com. Retrieved 2013-12-31.
- "Illegal StarLink™ GM Corn Resurfaces in Saudi Arabian". Greenmedinfo.com. 2013-08-16. Retrieved 2013-12-31.
- GMO Safety - Overview on biosafety research projects on genetically modified maize funded by the Federal Ministry of Education and Research (BMBF)
- Co-Extra - research project on coexistence and traceability of GM and non-GM supply chains