MON-ØØ531-6 - Bollgard™ cotton | BCH-LMO-SCBD-14775 | Living Modified Organism | Biosafety Clearing-House


Living Modified Organism (LMO)

Decisions on the LMO Risk Assessments  
last updated: 23 Jan 2023
Living Modified Organism identity
The image below identifies the LMO through its unique identifier, trade name and a link to this page of the BCH. Click on it to download a larger image on your computer. For help on how to use it go to the LMO quick-links page.
Bollgard™ cotton
The cotton (Gossypium hirsutum) was modified for insect resistance through the expression of Bacillus thuringiensis crystal protein (delta-endotoxin) Cry1Ac, which has a pore-forming mode of action in the midgut of feeding insects. The Cry1Ac protein confers resistance to Lepidoptera insects, such as cotton bollworm, tobacco budworm and pink bollworm. The modified cotton additionally contains an antibiotic resistance cassette (Escherichia coli neomycin phosphotransferase II) for kanamycin selection during transformation of the plants. 
The term “Recipient organism” refers to an organism (either already modified or non-modified) that was subjected to genetic modification, whereas “Parental organisms” refers to those that were involved in cross breeding or cell fusion.
Cultivar Coker 312
  • MON-89924-2 - Bollgard™ cotton
    | Monsanto | Resistance to antibiotics (Kanamycin), Resistance to diseases and pests (Insects, Lepidoptera (butterflies and moths))
  • MON-ØØ757-7 - Bollgard™ cotton
    | Monsanto | Resistance to antibiotics (Kanamycin), Resistance to diseases and pests (Insects, Lepidoptera (butterflies and moths))
Characteristics of the modification process
  • Agrobacterium-mediated DNA transfer
Some of these genetic elements may be present as fragments or truncated forms. Please see notes below, where applicable.
  • BCH-GENE-SCBD-15001-5 Neomycin Phosphotransferase II | Escherichia coli (ECOLX)
    Protein coding sequence | Resistance to antibiotics (Kanamycin)
  • BCH-GENE-SCBD-14986-6 Cry1Ac | Bacillus thuringiensis (Bt, Bacillus, BACTU)
    Protein coding sequence | Resistance to diseases and pests (Insects, Lepidoptera (butterflies and moths))
  • BCH-GENE-SCBD-100366-6 CaMV Enhanced 35S promoter | Cauliflower mosaic virus (CaMV)
  • BCH-GENE-SCBD-103856-6 α' subunit of β-conglycinin gene terminator | Glycine max (Soybean, Soya bean, Soya, SOYBN)
  • BCH-GENE-SCBD-100269-8 Nopaline Synthase Gene Terminator | Agrobacterium tumefaciens (Agrobacterium)
  • BCH-GENE-SCBD-100287-7 CaMV 35S promoter | Cauliflower mosaic virus (CaMV)
  • BCH-GENE-SCBD-15033-8 3"(9)-O-aminoglycoside adenyltransferase | Escherichia coli (ECOLX)
    Protein coding sequence | Resistance to antibiotics (Streptomycin)
  • BCH-GENE-SCBD-101416-6 Ti plasmid right border repeat | Agrobacterium tumefaciens (Agrobacterium)
    Plasmid vector
The modified cotton contains two gene cassettes: Bacillus thuringiensis cry1Ac and Escherichia coli neomycin phosphotransferase II (nptII).

The cry1Ac coding sequence is under control of Cauliflower mosaic virus (CaMV) 35S enhanced promoter and Glycine max α' subunit of β-conglycinin terminator. See notes below about the partial cry1Ac cassette and antibiotic resistance gene aad.

The nptII coding sequence is under control of a CaMV 35S promoter and and Agrobacterium tumefaciens nopaline synthase terminator.

  • Due to the constitutive nature of the viral promoters, high levels of expression are expected in all plant tissues.
  • The cry1Ac coding sequence was codon-optimized for expression in plants. The codon optimization resulted in a single amino acid change (leucine substituted for serine) at position 766 (L766S). The sequence was originally sourced from B. thuringiensis subsp. kurstaki HD-73.
  • Southern blot analysis indicated that the LMO contains a single active copy and a partial inactive copy of the cry1Ac gene both of which are linked.
  • The plasmid also contains the antibiotic resistance 3"(9)-O-aminoglycoside adenylyltransferase (aad) gene. This gene confers resistance to the antibiotics spectinomycin and streptomycin, and facilitated the selection of bacteria containing the plasmid in the initial steps of transforming the cotton tissue. The aad gene is under the control of a bacterial promoter. Studies using ELISA testing have indicated that there there is no detectable expression of the aad gene in the modified line.
LMO characteristics
  • Other (Industrial use)
Detection method(s)
Additional Information
The cry1Ac gene found in the modified cotton is almost identical to that found in nature and in commercial Bt spray formulations.

Cry proteins, of which Cry1Ac is only one, act by selectively binding to specific sites localized on the lining of the midgut of susceptible insect species. Following binding, pores are formed that disrupt midgut ion flow, causing gut paralysis and eventual death due to bacterial sepsis.

Cry1Ac only acts on the larvae of lepidopteran insects (moths and butterflies), due to the presence of specific binding sites (receptors) in the target insects, which are not found in other types of insects. There are no receptors for delta-endotoxins of Bacillus thuringiensis on the surface of mammalian intestinal cells and therefore, livestock animals and humans are not susceptible to these proteins.