DAS-21Ø23-5 - Insect-resistant cotton | BCH-LMO-SCBD-14938 | Living Modified Organism | Biosafety Clearing-House


Living Modified Organism (LMO)

Decisions on the LMO Risk Assessments  
last updated: 10 Apr 2013
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.
Insect-resistant cotton
The cotton line 3006-210-23 was genetically engineered to resist attack from lepidopteran insect pests such as the cotton bollworm, pink bollworm, tobacco budworm, beet armyworm, and soybean looper. This insect resistance is conferred by the cry1Ac gene, originally isolated from the common soil bacterium Bacillus thuringiensis (Bt) var. kurstaki.
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.
Line ‘Germain’s Acala GC510’
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-14986-6 Cry1Ac | Bacillus thuringiensis (Bt, Bacillus, BACTU)
    Protein coding sequence | Resistance to diseases and pests (Insects, Lepidoptera (butterflies and moths))
  • BCH-GENE-SCBD-100362-7 Ubiquitin gene promoter | Zea mays (Maize, Corn, MAIZE)
  • BCH-GENE-SCBD-100363-5 ORF25 PolyA Terminator sequence | Agrobacterium tumefaciens (Agrobacterium)
  • BCH-GENE-SCBD-103900-3 4ocs∆Mas2' promoter
  • BCH-GENE-SCBD-15002-4 Phosphinothricin N-acetyltransferase gene | Streptomyces viridochromogenes (STRVR)
    Protein coding sequence | Resistance to herbicides (Glufosinate)
Coding sequences of Cry1A(c) and pat genes altered for optimal expression in plant cells.

Southern blot analysis demonstrated that event 3006-210-23 contains a single integration of the transgenic DNA, including one intact copy of the cry1Ac gene, one intact copy of the pat gene, and single, intact copies of each of the regulatory elements. Analysis also indicated that there was no integration of segments from the erythromycin resistance gene.
LMO characteristics
  • Fiber/textile
Additional Information
The cry1Ac gene produces the insect control protein Cry1Ac, a delta-endotoxin, in the plant tissues. 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 is insecticidal only when eaten by the larvae of lepidopteran insects (moths and butterflies), and its specificity of action is directly attributable to the presence of specific binding sites in the target insects. There are no binding sites for delta-endotoxins of B. thuringiensis on the surface of mammalian intestinal cells, therefore, livestock animals and humans are not susceptible to these proteins.