<p style="text-align: justify;">Cotton (<i>Gossypium hirsutum</i> L.) was grown commercially in over 80 countries with a combined production of 44.2 million metric tonnes of cotton seed and 24.8 million metric tonnes of cotton lint in 2006. The major producers of cotton seed and lint were China, the United States, India, Pakistan, Brazil, Uzbekistan and Turkey. Cotton is primarily grown for its seed bolls that produce fibres used in numerous textile products. About two thirds of the harvested cotton crop is seed, which is separated from the lint during ginning. The cotton seed is crushed to produce cottonseed oil, cottonseed cake (meal), and hulls. Cottonseed oil is used primarily as cooking oil, in shortening and salad dressing, and is used extensively in the preparation of snack foods such as crackers, cookies and chips. The meal and hulls are an important protein concentrate for livestock, and may also serve as bedding and fuel. Linters, or fuzz, which are not removed in ginning, are used in felts, upholstery, mattresses, twine, wicks, carpets, surgical cottons, and in industrial products such as rayon, film, shatterproof glass, plastics, sausage skins, lacquers, and cellulose explosives.</p>

<p style="text-align: justify;">Tobacco budworm (<i>Heliothis virescens</i>), pink bollworm (<i>Pectinophora gossypiella</i>), and cotton bollworm (<i>Helicoverpa zea</i>) are three of the most destructive pests of cotton. In the United States alone, the budworm/bollworm complex reduced total cotton yield 1.39% in 2003, while total yield loss to arthropod pests was 4.16%. No other pest caused greater than 1% yield reduction in 2003. Almost 74% of the United States cotton crop was infected with the budworm/bollworm complex in 2003. The combined costs of control and yield loss attributed to these pests has been as high as US$476 million per year. In Egypt, China and Brazil, pink bollworm commonly causes cotton losses of up to 20 percent. More insecticides are applied to conventionally grown cotton than any other single crop. Each year cotton producers around the world use nearly US$2.6 billion worth of pesticides such as aldicarb, phorate, methamidophos and endosulfan. Cotton pests, such as the tobacco budworm, have developed some resistance to many of the insecticides used to control them. In regions where insecticide-resistant populations have developed, budworm damage can reduce yields by 29%, despite an average of six insecticide applications each growing season.</p>

<p style="text-align: justify;">Event MON 15985 (tradename Bollgard II&reg;) was derived from the hybrid cotton variety DP50B, which was a cross between DP50 and transgenic cotton line MON 531, by biolistic transformation with plasmid DNA containing the cry2Ab2 gene originally isolated from <i>Bacillus thuringiensis</i> subsp. <i>kurstaki</i>. As a result, event MON 15985 expresses both the Cry1Ac and Cry2Ab2 insecticidal proteins. MON 15985 is intended to protect cotton from feeding by a range of Lepidopteran species including tobacco budworm (<i>Heliothis virescens</i>), pink bollworm (<i>Pectinophora gossypiella</i>), cotton bollworm (<i>Helicoverpa zea</i>), cabbage looper (<i>Trichoplusia ni</i>), saltmarsh caterpillar (<i>Estigmene acrea</i>), cotton leaf perforator (<i>Bucculatrix thurbeiella</i>), soybean looper (<i>Pseudoplusia includens</i>), beet armyworm (<i>Spodoptera exigua</i>), fall armyworm (<i>Spodoptera frugiperda</i>), yellowstriped armyworm (<i>Spodoptera ornithogoll</i>i) and European corn borer (<i>Ostrinia nubilalis</i>). Monsanto has proposed cotton line MON 15985, with its two insecticidal proteins, as a means to provide more effective insect resistance management.</p>

<p style="text-align: justify;">As with other <i>B. thuringiensis</i>-derived delta-endotoxins, the Cry1Ac and Cry2Ab2 proteins exert their insecticidal activity by binding to specific receptors located on the brush border midgut epithelium of susceptible insect species. Following binding, cation-specific pores are formed that disrupt midgut ionic equilibrium leading to gut paralysis and eventual death due to bacterial sepsis. Cry1Ac and Cry2Ab2 are highly selective and are only active against Lepidopteran insects. These proteins do, however, interact with different receptor sites in the target insects and it is expected that &ldquo;stacking&rdquo; these traits will result in increased protection against insect attack and a delay in the development of resistant insect populations.</p>

<p style="text-align: justify;">In addition to the <i>cry</i> genes conferring insect resistance, MON 15985 also contains the <i>nptII</i> and <i>aad</i> selectable marker genes (derived from the parental cotton line containing event 531) and the beta-D-glucuronidase (GUS) encoding <i>uidA</i> gene from <i>Escherichia coli</i>. This latter gene was introduced as a visually scorable marker gene to identify transformed plantlets in tissue culture. The GUS enzyme can be used to catalyze a colorimetric reaction resulting in the production of a blue colour in transformed cells.</p>

<p style="text-align: justify;">This product description will focus on those aspects of the risk assessment pertaining to the <i>cry2Ab2</i> and <i>uidA</i> gene products. For additional information on the safety assessment of the <i>cry1Ac</i> and <i>nptII</i> gene products, the reader is directed to the product description for line MON 531.</p>
