Editing Genetically modified maize (section)

=== Gene flow ===
[[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,<ref>{{cite web | work = GMO Compass | date = 5 June 2009 | url = http://www.gmo-compass.org/eng/news/447.mexico_controlled_cultivation_genetically_modified_maize.html | title = Mexico: controlled cultivation of genetically modified maize | archive-url = https://web.archive.org/web/20131005010033/http://www.gmo-compass.org/eng/news/447.mexico_controlled_cultivation_genetically_modified_maize.html | archive-date = 5 October 2013 }}</ref> but because Mexico is the [[center of diversity]] for maize, gene flow could affect a large fraction of the world's maize strains.<ref>{{cite web | vauthors = Shanahan M | work = Science and Development Network | date = 10 November 2004 | url = http://www.scidev.net/en/news/warning-issued-on-gm-maize-imported-to-mexico.html | title = Warning issued on GM maize imported to Mexico }}</ref><ref>{{cite web | vauthors = Mantell K | work = Science and Development Network | date = 30 November 2001  | url = http://www.scidev.net/en/news/gm-maize-found-contaminating-wild-strains.html | title = GM maize found 'contaminating' wild strains }}</ref> A 2001 report in ''Nature'' presented evidence that Bt maize was cross-breeding with unmodified maize in Mexico.<ref name="pmid11734853">{{cite journal | vauthors = Quist D, Chapela IH | title = Transgenic DNA introgressed into traditional maize landraces in Oaxaca, Mexico | journal = Nature | volume = 414 | issue = 6863 | pages = 541–3 | date = November 2001 | pmid = 11734853 | doi = 10.1038/35107068 | s2cid = 4403182 | bibcode = 2001Natur.414..541Q }}</ref> 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".<ref name="pmid11935145">{{cite journal | vauthors = Kaplinsky N, Braun D, Lisch D, Hay A, Hake S, Freeling M | title = Biodiversity (Communications arising): maize transgene results in Mexico are artefacts | journal = Nature | volume = 416 | issue = 6881 | pages = 601–2; discussion 600, 602 | date = April 2002 | pmid = 11935145 | doi = 10.1038/nature739 | s2cid = 195690886 | bibcode = 2002Natur.416..601K }}</ref> A 2005 large-scale study failed to find any evidence of contamination in Oaxaca.<ref>{{cite journal | vauthors = Ortiz-García S, Ezcurra E, Schoel B, Acevedo F, Soberón J, Snow AA | title = Absence of detectable transgenes in local landraces of maize in Oaxaca, Mexico (2003-2004) | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 102 | issue = 35 | pages = 12338–43 | date = August 2005 | pmid = 16093316 | pmc = 1184035 | doi = 10.1073/pnas.0503356102 | bibcode = 2005PNAS..10212338O | doi-access = free }}</ref> However, other authors also found evidence of cross-breeding between natural maize and [[transgenic maize]].<ref name="pmid19143938">{{cite journal | vauthors = 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 | display-authors = 6 | title = Transgenes in Mexican maize: molecular evidence and methodological considerations for GMO detection in landrace populations | journal = Molecular Ecology | volume = 18 | issue = 4 | pages = 750–61 | date = February 2009 | pmid = 19143938 | pmc = 3001031 | doi = 10.1111/j.1365-294X.2008.03993.x }}</ref>

A 2004 study found Bt protein in kernels of refuge corn.<ref>{{cite journal | vauthors = Chilcutt CF, Tabashnik BE | title = Contamination of refuges by Bacillus thuringiensis toxin genes from transgenic maize | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 101 | issue = 20 | pages = 7526–9 | date = May 2004 | pmid = 15136739 | pmc = 419639 | doi = 10.1073/pnas.0400546101 | bibcode = 2004PNAS..101.7526C | doi-access = free }}</ref>

In 2017, a large-scale study found "pervasive presence of transgenes and glyphosate in maize-derived food in Mexico"<ref>{{cite journal | vauthors = González-Ortega E, Piñeyro-Nelson A, Gómez-Hernández E, Monterrubio-Vázquez E, Arleo M, Dávila-Velderrain J, Martínez-Debat C, Álvarez-Buylla ER | title = Pervasive presence of transgenes and glyphosate in maize-derived food in Mexico. | journal = Agroecology and Sustainable Food Systems | date = November 2017 | volume = 41 | issue = 9–10 | pages = 1146–61 | doi = 10.1080/21683565.2017.1372841 | s2cid = 44076727 | url = https://www.uccs.mx/images/library/file/Agricultura_y_alimentacion/alisa/2017_gmo/Pervasive_presence_of_transgenes_in_maize_food_2017.pdf | access-date = 5 November 2017 | archive-date = 7 November 2017 | archive-url = https://web.archive.org/web/20171107023747/https://www.uccs.mx/images/library/file/Agricultura_y_alimentacion/alisa/2017_gmo/Pervasive_presence_of_transgenes_in_maize_food_2017.pdf | url-status = dead }}</ref>