Final health and environmental risk assessment of genetically modified cotton 281-24-236 x 3006-210-23 (MXB-13). Scientific opinion on insect resistant and glufosinate-tolerant genetically modified cotton MXB-13 from Dow AgroSciences for food and feed uses, import and processing under Regulation (EC) No 1829/2003 (Application EFSA/GMO/NL/2005/16). Opinion of the Panel on Genetically Modified Organisms of the Norwegian Scientific Committee for Food Safety.

Genetically modified cotton 281-24-236 x 3006-210-23 (MXB-13) from Dow AgroSciences was produced by conventional crossing of the single-event GM-cotton cultivars 281-24-236, which expresses the cry1F and pat genes, and 3006-210-23, which expresses the cry1Ac and pat genes. The resulting stacked event cotton MXB-13 expresses all three proteins: Cry1Ac, Cry1F and the phosphinothricin-acetyl–transferase (PAT) enzyme. The Cry-proteins confer resistance against specific lepidopteran pests and the PAT-enzyme renders cotton MXB-13 tolerant to application of the herbicide glufosinate-ammonium. Updated bioinformatics analyses of the inserted DNA and flanking sequences in cotton MXB-13 have not indicated potential production of putative harmful toxins or allergens caused by the genetic modification. Genomic stability of the functional inserts and consistent expression of the cry1Ac, cry1F and pat genes have been shown over several generations of cotton MXB-13. Data from several field trials performed in the USA indicate that with the exception of the introduced traits, cotton MXB-13 is compositionally, phenotypically and agronomically equivalent to its conventional counterparts and other cotton cultivars. A 90-day sub-chronic oral toxicity study with rats and a 42-day nutritional assessment trial with broilers have not revealed adverse effects of cottonseed meal from cotton MXB-13 compared to meal from the conventional counterpart PSC355 and other cotton cultivars. Toxicity testing of the Cry1Ac, Cry1F and PAT proteins in repeated-dose dietary exposures with mice and rats did not indicate adverse effects. The Cry1Ac, Cry1F and PAT proteins produced in cotton MXB-13 do not show amino acid sequence resemblance to known toxins or IgE-dependent allergens, nor have they been reported to cause IgE-mediated allergic reactions. It is therefore unlikely that the Cry1Ac, Cry1F and PAT proteins will cause toxic or IgE-mediated allergic reactions to food or feed containing cotton MXB-13 compared to conventional cotton cultivars. Cotton is not cultivated in Norway, and there are no cross-compatible wild or weedy relatives of cotton in Europe. Based on current knowledge and with the exception of the introduced traits, the VKM GMO Panel concludes that cotton MXB-13 is nutritionally, compositionally, phenotypically and agronomically equivalent to and as safe as its conventional counterparts and other cotton cultivars. Considering the intended uses, which exclude cultivation, the VKM GMO Panel concludes that cotton MXB-13 does not represent an environmental risk in Norway.NO; PDF; vkm@vkm.n