Science in Society Archive

MON810 Genome Rearranged Again

Stability of All Transgenic Lines in Doubt

Dr. Mae-Wan Ho

This report has been submitted to the EFSA on behalf of I-SIS

The instability of transgenic lines is not exactly news, but something too seldom reported, being The Best Kept Secret of GM Crops [1], and even we in I-SIS have missed this item hidden in the final paragraphs of a technical paper published in 2003, which found new signs of instability in a transgenic maize that has been grown commercially since 1995.

Researchers from the Institute of Molecular Biology in Barcelona, Spain, analysed MON810 maize Certified Reference Material (CRM) obtained from the European Commission’s Institute for Reference Materials and Measurements (IRMM) and commercialised by Fluka (Buchs, Switzerland); using the most sophisticated and sensitive polymerase chain reaction (PCR) methods available [2]. They found that the transgene insert had rearranged and probably moved, yet again, from its whereabouts reported a year ago, when MON810 maize, along with at least 5 other lines were found to have rearranged, and no longer matched the genetic maps provided by the companies [3-5] (Transgenic Lines Proven Unstable, SiS 20; Unstable Transgenic Lines Illegal, SiS 21).

These initial discoveries [3-5] were so serious that on 28 November 2003, I wrote to Dr. William Moens, Head of the Service of Biosafety and Biotechnology (SBB), Scientific Institute of Public Health (IPH), which had reported one of the two different sets of data on transgenic inserts, and I raised two important issues [6]:

“First, there appears to be both major and minor inconsistencies between the results reported by your Institute and those reported by the French laboratories. Could that be due to methodological problems or to different samples of the same transgenic line being analysed? If the latter is the case, it would suggest that the transgenic lines are not only unstable (see below) but also non-uniform. In other words, they do not pass the DUS [Distinct, Uniform and Stable] test, which I understand, is required by European law [for a commercial variety].

“Second, the new EU Directive 2001/18/EC specifically requires event-specific molecular data documenting genetic stability (Annex IIIB) as a condition for market approval. In view of the finding that practically every transgenic insert has rearranged from that reported in the company’s dossier, it would indicate that the transgenic lines have failed the test of genetic stability, and are no longer the same lines that were risk assessed, and in some cases, placed on the market.

“For either or both those reasons, it would seem illegal, under European law, to grant those transgenic lines commercial approval; and the lines that have been approved should surely now be withdrawn.”

The reply from Dr. Moens came two days later. It stated [7]:

“I thank you very much for your email and related data. The experts of the Belgian Biosafety Council are just busy to evaluate in a hurry all these elements. Your email and data have been transmitted for further review.

“No doubt that the outcome of such analysis will be handled on a transparent way within delays that are not yet defined. (sic) I can guarantee you that I'll make you aware about our conclusions when legally possible.”

I never heard from Moens or anyone else from SBB again.

In December 2007, I resent my message and Moens’ reply to him, to remind him that I was still awaiting his answer, but received nothing so far. The reason seems to be that our regulators have allowed the companies to submit new data, and probably even new certified reference materials, in order to justify continued market approval, which is still illegal .

The Spanish finding highlights how unstable a transgenic line could be. Specifically, the Spanish team characterized the 3’ region (tail end) of the transgenic insert, and found it was no longer in the long terminal repeat (LTR) of the alpha Zein gene cluster of the maize genome, as reported a year ago [3-5]. Furthermore, they failed to get any PCR product from the wild type maize genome that corresponds to the site at which the transgenic insert had landed. That is indicative of substantial genome scrambling at the MON810 transgenic insertion site; and there are other signs that further sequences have been deleted from the original insert.

Recently, researchers in the Industrial Toxicology Research Centre in Marg Lucknow, India, have also analysed the MON810 insert using multiple PCR primers, and came to the same conclusion [8]: their finding “confirms the structural instability of MON810 transgene cassettes.”  Contrary to Monsanto’s claim that nptII is absent in MON810, they consistently found the presence of nptII as well as Tnos in their sample. This inconsistency has been noted previously [5].

Another research team at the University of Florence, Italy, has just published their characterization of the 3’ insertion site of MON810 [9] and identified scrambled sequences belonging to the maize HECT E3 ubiquitin ligase. They found several new mRNAs that are fusion proteins of the truncated Cry1Ab and the uibiquitin ligase sequences, the safety implications of which are totally unknown.

For at least the past ten years, I have been looking for credible evidence that transgenic line is stable and found none. That remains true to-date. The transgenic insert is not the same as a natural piece of DNA. Transgenic DNA has features that make it behave somewhat like a loose cannon even after it has inserted into a genome, it can jump elsewhere in the same genome, scrambling the genome on the way, or it can insert into the genome of another cell [10] ( Horizontal Gene Transfer from GMOs Does Happen, SiS 38) to wreak the same unpredictable havoc, and worse, to activate cancer genes with its revved up promoter that makes the transgene over-express out of control.

Article first published 11/03/08


  1. Ho MW. The best kept secret of GM crops. Witness statement in ACRE Open Hearing on the criticisms of T25 GM maize risk assessment, February 2002,
  2. Hernández M, Pla M, Esteve T, Prat S Puigdomènech P and Ferrando A.  A specific real-time quantitative PCR detection system for event MON810 in maize YieldGard based on the 3’-transgene integration sequence. Transgenic Research 2003, 170-89.
  3. Collonier C, Berthier G, Boyer F, Duplan M-N, Fernandez S, Kebdani N, Kobilinsky A, Romanuk M, Bertheau Y. Characterization of commercial GMO inserts: a source of useful material to study genome fluidity. Poster presented at ICPMB: International Congress for Plant Molecular Biology (n°VII), Barcelona, 23-28th June 2003. Poster courtesy of Pr. Gilles-Eric Seralini, Président du Conseil Scientifique du CRII-GEN,
  4. Ho MW. Transgenic lines proven unstable. Science in Society 20, 35, 2003.
  5. Ho MW. Unstable transgenic lines illegal. Science in Society 21, 23, 2003.
  6. Ho MW. E-mail message to Dr. William Moens, Service of Biosafety and Biotechnology (SBB), Scientific Institute of Public Health (IPH), 28 November 2003.
  7. Moens W. Reply to Ho MW. 30 November 2003.
  8. Singh CK, Ojka A, Kamle S and Kachru DN. Assessment of cry1Ab transgene cassette in commercial Bt corn MON810: gene, event, construct & GMO specific concurrent characterization. Nature Protocols 2007, DOI: 10.1038/nprot.2007.440,
  9. Rosati A, Bogani P, Santarlasci A and Buiatti M. Characterisation of 4’ transgene insertion site and derived mRNAs in MON810 YieldGard maize. Plant Mol Biol DOI 10.1007/s11103-008-9315-7
  10. Ho MW and Cummins J. Horizontal gene transfer really happens. Science in Society 38 (to appear).

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