Brassica napus modified for altered fatty acid metabolism | BCH-LMO-SCBD-101385 | Living Modified Organism | Biosafety Clearing-House

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Living Modified Organism (LMO)

Decisions on the LMO Risk Assessments  
published: 20 Sep 2010 last updated: 18 Sep 2012
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.
Brassica napus modified for altered fatty acid metabolism
EN
NBM99-ClFatB4; NBM99-EnClFatB4
No
In these GM oilseed rape plants a the new acyl-[ACP] thiosterase is expressed that specifically catalyses the synthesis of the medium chain fatty acids myristic and palmitic acids. These fatty acids occur naturally in other plant oils used for human consumption (e.g. coconut oil).

The modified oilseed rape plants were selected using the nptII-gene product NPT. Hence the plants must be considered to be resistant against antibiotics like neomycin and kanamycin.
EN
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/breeding line: Drakkar
EN
Characteristics of the modification process
pNBM99-ClFatB4 and pNBM99-EnClFatB4
EN
  • 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-101362-5 Acyl-acyl carrier protein thioesterase | Cuphea lanceolata (Cigar Flower)
    Protein coding sequence | Changes in quality and/or metabolite content (Lipid and fatty acids)
  • BCH-GENE-SCBD-100287-7 CaMV 35S promoter | Cauliflower mosaic virus (CaMV)
    Promoter
  • BCH-GENE-SCBD-100290-6 CaMV 35S terminator | Cauliflower mosaic virus (CaMV)
    Terminator
  • BCH-GENE-SCBD-103920-2 Acyl-acyl carrier protein thioesterase promoter | Cuphea lanceolata (Cigar Flower)
    Promoter
  • BCH-GENE-SCBD-103921-2 Acyl-acyl carrier protein thioesterase terminator | Cuphea lanceolata (Cigar Flower)
    Terminator
Notes about the Transcriptional regulator(s) specific to this LMO

Acyl-[ACP] thioesterases hydrolyse the thioester ligation between the ACP (acyl carrier protein) and the synthesised acyl chain in fatty acid biosynthesis. Myristic and palmitic-[ACP] are substrates of the Cuphea lanceolata-derived enzyme which is encoded by the acyl-[ACP] thioesterase gene (ClFatB4). As a result of the formation of this enzyme the oil produced in the seeds of the genetically modified (GM) oilseed rape plants contains up to 20% myristic acid (C14:0), which is not normally present in rapeseed oil, and increased levels of palmitic acid (C16:0).

Expression of the ClFatB4 gene contained in the GM oilseed rape plants is driven by its own seed-specific promoter and its termination signal. In one of the two constructs used, expression should be amplified by the upstream position of the fourfold enhancer of the CaMV 35S promoter.

In the GM oilseed rape plants the newly formed acyl-[ACP] thiosterase catalyses the same reaction as corresponding enzymes which occur naturally in the seeds of other (wild and cultivated) plant species. Myristic and palmitic acids, the fatty acids which are newly formed or occur in higher concentrations in the rapeseed oil, occur naturally in other plant oils used for human consumption (e.g. coconut oil).

Notes about the Other(s) sequence(s) specific to this LMO

The GM plants contain sequences from the left and right border regions of the TL -DNA of the plasmid pTiB6S3 from Agrobacterium tumefaciens. Depending on the gene products of the vir region of the helper plasmid pMP90RK present in the Agrobacterium strain used for the transformation, which was not transferred to the plants, these sequences effected the integration of the genes located between the border region into chromosomes of the oilseed rape plants. These border regions of the Ti plas-mids have no function in the GM oilseed rape plants and are not expected to cause any changes in the plants.
EN
LMO characteristics
EN
  • Research
  • Food (field trial, not for common use)
Detection method(s)
EN
Additional Information
Acyl-[ACP] thioesterases hydrolyse the thioester ligation between the ACP (acyl carrier protein) and the synthesised acyl chain in fatty acid biosynthesis. Myristic and palmitic-[ACP] are substrates of the Cuphea lanceolata-derived enzyme which is encoded by the acyl-[ACP] thioesterase gene (ClFatB4).

Expression of the ClFatB4 gene contained in the GM oilseed rape plants is driven by its own seed-specific promoter and its termination signal. In one of the two constructs used, expression should be amplified by the upstream position of the fourfold enhancer of the CaMV 35S promoter.
In the GM oilseed rape plants the newly formed acyl-[ACP] thiosterase catalyses the same reaction as corresponding enzymes which occur naturally in the seeds of other (wild and cultivated) plant species.

Myristic and palmitic acids, the fatty acids which are newly formed or occur in higher concentrations in the rapeseed oil, occur naturally in other plant oils used for human consumption (e.g. coconut oil).

Due to the substrate specificity of neomycin phosphotransferase, no new metabolic products are ex-pected to arise in the GM plants in the absence of substrate under field conditions. Since high concentrations of the relevant antibiotics are not present in soil, the neomycin phosphotransferase does not confer any selection advantage to the GM plants under field conditions. There is no evidence to suggest that this enzyme is toxic to plants, animals, microorganisms or humans.The nptII gene transferred to the GM plants encodes the enzyme neomycin phosphotransferase. It was inserted as a marker gene for selecting transformed plant cell. The neomycin phosphotransferase gene is a type II aminoglycoside 3'-phosphotransferase (APH(3')II), which catalyses the ATP-dependent phosphorylation of the 3'-OH group of the aminohexose ring of specific aminoglycoside antibiotics, causing these to become inactivated. The enzyme is characterised by its high substrate specificity. The antibiotics kanamycin, neomycin, geneticin, butirosin, gentamicin A and B, and paromomycin belong to the APH(3')II enzyme substrates. Clinically relevant gentamicins and other aminoglycosides and aminocyclitoles used in human medicine do not belong to the substrate spectrum of the APH(3')II enzyme. Kanamycin and neomycin are, however, widely used in veterinary medicine.
EN
Records referencing this document Show in search
Record type Field Record(s)
Living Modified Organism Recipient Organism” or “Parental Organisms 1
Living Modified Organism Related LMO(s) 8
Country's Decision or any other Communication Living modified organism(s) 2
Risk Assessment generated by a regulatory process Living modified organism(s) 2