DAS-24236-5 - Insect-resistant cotton | BCH-LMO-SCBD-14940 | Living Modified Organism | Biosafety Clearing-House


Living Modified Organism (LMO)

Decisions on the LMO Risk Assessments  
published: 07 Jun 2006 last updated: 08 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 281-24-236 was genetically engineered to resist attack from Lepidopteran insect pests such as the tobacco budworm, cotton bollworm, beet armyworm, and soybean looper. This insect resistance is conferred by the cry1F gene, originally isolated from the common soil bacterium Bacillus thuringiensis (Bt) var. aizawai.
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.
Lepidopteran-resistant cotton, with insect resistance conferred by the cry1F gene from the common soil bacterium Bacillus thuringiensis (Bt) var. aizawai.

Coding sequences of Cry1F and pat genes altered for optimal expression in plant cells. The Cry1F protoxin is a chimeric, full-length δ-endotoxin comprised of the core toxin of Cry1F from Bacillus thuringiensis var. aizawai strain PS81I and nontoxic portions of Cry1Ca3 and Cry1Ab1 proteins. Together, the portions of Cry1Ca3 and Cry1Ab1 that comprise the chimeric C-terminal domain are approximately those removed by alkaline proteases during the formation of the active Cry1F core toxin.
LMO characteristics
  • Fiber/textile
Additional Information
The cry1F gene produces the insect control protein Cry1F, a delta-endotoxin, in the plant tissues. Cry proteins, of which Cry1F 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. Cry1F 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.