DAS-Ø15Ø7-1 - Herculex™ I maize | BCH-LMO-SCBD-14841 | Living Modified Organism | Biosafety Clearing-House

Living Modified Organism (LMO)
Decisions on the LMO Risk Assessments  
published: 05 Jun 2006 last updated: 08 Feb 2019
Living Modified Organism identity
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Herculex™ I maize
Corn modified with the insertion of the Cry1F gene from Bacillus thuringiensis to confer resistance to the European corn borer (Ostrinia nubilalis). A transformation cassette coding for phosphinothricin (PPT) herbicide tolerance, specifically glufosinate ammonium, was also inserted into the organism.
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.
Characteristics of the modification process
PHI8999A derived from plasmid PHP8999
  • Biolistic / Particle gun
Some of these genetic elements may be present as fragments or truncated forms. Please see notes below, where applicable.
Notes about the Other(s) sequence(s) specific to this LMO

DNA fragment PHI8999A contains two adjacent plant gene expression cassettes for the cry1F and pat genes (see below). Transcription of the cry1F gene was directed by the promoter and first exon and intron of the maize ubiquitin gene. The 3' terminator sequence used was the 3' polyadenylation signal from ORF25 (Agrobacterium tumefaciens) (see footnote*). Transcriptional regulation of the pat gene from Streptomyces viridochromogenes was via promoter and terminator sequences derived from the 35S transcript of cauliflower mosaic virus (CaMV). The coding sequence of both genes has been optimised to achieve a high level of expression in maize.

The sequences of the complete cry1F and pat genes are identical to those in the original plasmid. The proteins produced in the modified plants are the ones intended, including a leucine residue (replacing a phenylalanine) at position 604 (of 605 amino acids in total) of Cry1F. This modification was introduced to create a specific restriction site for cloning purposes.


Footnote *:  The EFSA document (see below) indicates that the 3’ sequence from the Agrobacterium tumefaciens mannopine synthase gene was used as terminator of the cry1F gene.
LMO characteristics
  • Food
  • Feed
  • Biofuel
Detection method(s)
Molecular analyses of the transformed plant show that the event TC1507 contains one site of integration of the introduced DNA which includes a full-length of the DNA fragment used for transformation (i.e. the ~6235 bp of DNA cassette containing the cry1F and pat genes) and an additional copy of the cry1F gene lacking the majority of the associated ubiquitin regulatory sequences.

Southern analysis using a cry1F probe carried out by the European Food Safety Authority (EFSA; see document below) revealed the presence of two cry1F inserts. The first represented the intact gene from the expression cassette. The second insert was a truncated cry1F  fragment of 335bp, which is located at the 5’ end of the insertion locus. In addition, analysis of the sequences adjacent to the insert of fragment PHI8999A revealed DNA fragments that correspond to small segments from PHI8999A, including incomplete sequences from the pat gene, the maize ubiquitin promoter and the terminator from Agrobacterium. Furthermore, different fragments of chloroplast DNA and a number of sequences with similarity to retrotransposons are also present in the border region of the insert.