Hazardous Virus Gene Discovered in GM Crops after 20 Years

Farm Wars
Dr Mae-Wan Ho ISIS

SIS has warned against the CaMV 35S promoter and called for all affected GM crops to be withdrawn since 1999 while damning evidence on its safety continues to emerge

A European Food Safety Authority (EFSA) scientist has just discovered that major GM crops and products the regulatory agency has been approving for commercial release over the past 20 years contain a potentially dangerous virus gene. The gene – Gene VI – overlaps with the cauliflower mosaic virus (CaMV) 35S promoter. The CaMV 35S promoter is the commonest, most widely used regulatory sequence for driving gene expression in GM crops. This momentous discovery was published in a little known journal during the holiday season at the end of 2012 [1], and would have passed unnoticed had it not caught the attention of Jonathan Latham and Alison Wilson of Independent Science News. They described the finding and carried out a proper retrospective risk assessment on the Gene VI fragment in a report posted on their website [2]. This attracted so much public attention that EFSA and its counterpart Food Standards Australia New Zealand (FSANZ) are said [3] to have jointly “shredded” the scientific paper on which Latham and Wilson’s report is based.

EFSA and FSANZ say the allegations that the viral Gene VI hidden in the CaMV 35S promoter might not be safe for human consumption and could disturb the normal functioning of crops are completely false. A spokesperson from FSANZ states: “Human exposure to DNA from the cauliflower mosaic virus and all its protein products through consumption of conventional foods is common and there is no evidence of any adverse health effects.”

Ironically, the first author of the scientific paper [1] Nancy Podevin is from EFSA, while the second author Patrick Du Jardin is at University of Liège in Belgium; and EFSA GMO Panel is acknowledged for “advice given”. The main thrust of the paper is in fact a screening of Gene Vi amino acid sequence against existing databases for known allergens and finding none; thereby offering false reassurance while the real hazards are swept under the carpet.

This is not the first time that the safety of CaMV 35S promoter is being questioned.

Serious concerns had been raised over the safety of CaMV 35S promoter

ISIS first raised concerns over the CaMV 35S and similar promoters in a paper published in the journal Microbial Ecology in Health and Disease in 1999 [4] (Cauliflower Mosaic Viral Promoter – A Recipe for Disaster?) when it was discovered to have a recombination (fragmentation) hotspot that would enhance unintended horizontal gene transfer and recombination, and in the process create new viruses or activate old ones, and trigger cancer in animal cells by well-known processes of ‘insertion carcinogenesis’. The CaMV 35S promoter was known to be highly promiscuous in being able to function in most if not all species across the living world (including human cells, as it turned out). To make matters worse, many synthetic versions of the promoter have been constructed with additional enhancers for gene expression and sequences from other sources, all of which increase its instability (tendency to fragment) as well as its ability to drive inappropriate gene expression. (We also reported the overlap of the 35S promoter with Gene VI, so this knowledge must have been widely known, although its safety implications were not obvious, at least to us.)

As a precautionary measure, we strongly recommended that all transgenic crops containing CaMV 35S or similar promoters should be immediately withdrawn from commercial production or open field trials.

Our first paper brought a swift reaction. Within two days of its being published online, someone managed to solicit at least nine critiques, including one from Monsanto, which were posted on a website funded by the biotech industry and widely circulated on the internet. The critiques varied in tone from moderately polite to outright abusive. We wrote a detailed rebuttal, which was likewise circulated and posted to the same website, and have not received any replies from our critics since. But in January 2000, Nature Biotechnology published a distorted, one-sided and offensive account of our paper, concentrating on the criticisms and ignoring our rebuttal completely, which we published in the same journal that carried the first paper[5] (Hazards of Transgenic Plants Containing the Cauliflower Mosaic Viral Promoter).

Regulators’ objections irrelevant and false

It is of interest that the objections for ‘shredding’ the scientific paper of Podevin and du Jardin [1] and Latham and Wilson’s report [2] are exactly the ones used against us. The first objection is that humans have been eating the CaMV for millennia without ill effects; the second is that the CaMV 35S promoter is only active in plants and certainly not in animal or human cells.

Our rebuttal to the first objection is that the intact CaMV, consisting of the CaMV genome wrapped in its protein coat, is not infectious for human beings or for other non-susceptible animals and plants, as is well-known; for it is the coat that determines host susceptibility in the first instance. So eating the intact virus is of little consequence. However, the naked or free viral genomes (and parts thereof) are known to be more infectious and have a wider host-range than the intact virus. Furthermore, the synthetic CaMV 35S promoters are very different from the natural promoters, and are both much more aggressive as promoters driving inappropriate gene expression as well as more prone to fragment and recombine.

The second objection – that CaMV 35S is not active in animals and human cells – is simply false as we discovered in the scientific literature dating back to 1989, and pointed this out in a third paper [6] (CaMV 35S promoter fragmentation hotspot confirmed, and it is active in animals ). The CaMV 35S promoter was found to support high levels of reporter gene expression in mature Xenopus oocytes [7], and to give very efficient transcription in extracts of nuclei from HeLa cells (a human cell line) [8].

What of our original concern over the CaMV 35S promoter activating viruses in host genomes? There is new evidence suggesting that the CaMV 35S promoter may indeed enhance the multiplication of disease-associated viruses including HIV and cytomegalovirus through the induction of proteins required for transcription of the viruses [9] (New Evidence Links CaMV 35S Promoter to HIV Transcription).

It is in this context that Latham and Wilson’s report for ISIS [10] (Potentially Dangerous Virus Gene Hidden in Commercial GM Crops, SiS 57) should be read, which fully justifies our original recommendation for a total recall of the affected GM crops. This same call is now repeated by Latham and Wilson.

Related:  Regulators Discover a Hidden Viral Gene in Commercial GMO Crops

NEW ROW OVER GM FOOD

Express
by John Ingham

NEW fears were raised over genetically modified food yesterday after researchers claimed regulators had missed an "unsuspected viral gene" in widely used crops.

A study published last month found that the commonest modification in GM crops includes a "significant fragment of a viral gene" known as Gene VI.

The study by European Food Standards Agency experts published in the journal GM Crops and Food said the gene “might result in unintended phenotypic changes" which means it could have unintended genetic or environmental consequences. The report comes with ministers backing GM foods and claiming the technology is needed to feed the world's growing population.

Earlier this month Environment Secretary Owen Paterson said the Government should not be afraid of making the case to the public about the "potential benefits of GM beyond the food chain, for example, reducing the use of pesticides and inputs such as diesel".

But yesterday critics claimed the new discovery suggests that some GM crops could pose risks for consumers and the environment.

Dr Jonathan Latham of Independent Science News said: "This finding has serious ramifications for crop biotechnology and its regulation, but possibly even greater ones for consumers and farmers.

"This is because there are clear indications that this viral gene might not be safe for human consumption.

"It also may disturb the normal functioning of crops, including their natural pest resistance."

Gene VI is found in some of the most widely grown FGM crops including weedkiller-resistant soya beans and maize.

Two thirds of GM crops approved in the US contain the hitherto unidentified viral gene.

GM crops have been given commercially attractive properties - such as weedkiller or pest resistance - by having new genes inserted.

These genes are usually taken from species with which the crop could not breed naturally.

Last night Pete Riley of the GM Freeze pressure group said: “This discovery of this previously unidentified gene in GM crops raises serious concern about the safety of GM food and feed.

"It totally undermines claims that GM technology is safe, precise and predictable.

“The very existence of Gene VI has been missed for many years, so we don’t know what implications it might have.

"It is impossible to say if this has already resulted in harm to human or animal health, and since there is still no GM labelling in places like the US where GM is more common in the diet, no epidemiological studies can be carried out.

"Possible harmful effects of GM Organisms could easily be lost in the general morass of ailments which vets and medics have to deal with on a daily basis, especially if these were as result of low level exposure over several years, and the link to GM could take many years to establish that way.

“This is a clear warning the GM is not sufficiently understood to be considered safe.

But the biotech industry insists that its products have undergone rigorous checks - and have been eaten safely by million worldwide.

Dr Julian Little, chairman of the Agricultural Biotechnology Council, said: “The claims by Latham and Wilson were made in a blog posting, not a peer-reviewed publication. The original article by Podevin and du Jardin states that there are no elements present in the GM crops tested which are similar to known toxic and allergenic proteins.

“The GMO risk assessment carried out by EFSA is the central element of the strictest, science-based crop authorisation procedure in the world. This study is just a small part of what is a comprehensive and highly complex scrutiny process. “Over the past 25 years, the European Commission has funded more than 130 research projects involving 500 independent research groups which have found no higher risks to the environment or food chain from GM crops than from conventional plants and organisms. "Furthermore, nearly three trillion meals containing GM ingredients have been eaten without a single substantiated case of ill-health. The combination of these two facts can give consumers a huge amount of confidence in the safety of GM crops.”

The Department for Environment Food and Rural Affairs said the viral gene in the research occurs naturally and will be present in non-GM food.

A spokesman said: “The world’s population is growing which means people will need more food and there will be a greater demand for water, energy and land.

“GM is one of the tools in the box that could help us tackle these challenges. But our top priority is safeguarding human health and the environment so any decisions on GM would have to be based on rigorous scientific evidence.”

The European Food Safety Authority has highlighted that the data published in the paper do not represent a new discovery of a viral gene and nor do they indicate safety concerns surrounding previously evaluated GM crops.