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Why A Field Trial Is A Release by Sean Weaver

One of the biggest environmental issues with the use of GMOs is the ability to contain viable genetic material so that it does not spread to non-target species, crops or organisms. If viable DNA could only be transmitted by means of sexual reproduction then containment would be relatively easy. In the case of a crop like pine trees we would simply not allow the crop to reach sexual maturity in a field trial, or we would engineer the crop to not produce reproductive structures. For animals we could prevent mating with non-GMO stock.

The movement pathways for viable DNA, however, are not that simple. In fact sexual reproduction is only one of the ways that DNA is able to move around. Another pathway is called horizontal gene transfer (HGT). Research into HGT has reached new heights in recent years and was also being updated during the course of the Royal Commission. One only needs to run a search on databases for international peer reviewed research papers and one will come up with many recent examples of research into HGT. Horizontal gene transfer is the transfer of DNA sequences outside sexual reproduction.

Containment

In order to contain genetic material one needs to establish effective barriers to the movement viable DNA into the wider environment. The normal pathways of DNA movement need to be removed or significantly obstructed.

There are many pathways through which viable genetic material can travel. These include sexual reproduction and dispersal mechanisms (e.g. pollen, fruit, gametes, embryos, offspring), and non-sexual gene transferring material (e.g. horizontal gene transfer between bacteria and each other and between bacteria and higher organisms). Horizontal gene transfer only requires the exposure of viable genetic material to living bacteria. This genetic material need not be in a living organism, but could be in decaying material, faeces, or in the gut.

This means that pathways for genetic exchange for a genetically Modified Organism (GMO) include the passage of DNA:-  From living cells of a GMO to bacteria either in the gut or in the soil  from living cells of a GMO to the gut of parasites that can then disperse and reproduce at some distance of the GMO  from dead or decaying cells of a GMO to bacteria  in the form of naked GMO DNA that is attached to soil particles or contained in dung  from bacteria to other organisms in the food chain.

This passage of genetic material can then include any pathway by which bacteria travel in a viable form, such as by means of inoculation of soils, movement in ground water and surface water flows, in effluent that is carried elsewhere, on dust particles that are wind blown, in the gut of blood feeding insects and other parasites. Fences at the edge of a field trial present no barrier to the movement of DNA. GMO DNA therefore will not be restricted to the fields of field trials.

If genetic material is transferred horizontally from bacteria to other organisms and taken up into the genome of those organisms then the pathways for the movement of transgenes (the genetically engineered gene) will include the normal movements and reproductive strategies for those organisms. Plants, animals and bacteria are well equipped with dispersal strategies that have proven effective now for many millions of years.

Given that field trials are supposed to be testing the safety of GMOs (although little funding is being allocated to this task), if the GMO is already in the environment in a field trial, it is ecologically speaking, already released.

Laboratory Door

Many groups opposing genetic modification have drawn the line at the laboratory door. This in no way suggests that there is an absolute distinction to be made between the inside and the outside of a laboratory. What it does acknowledge, however, is that there is a significant and substantial difference in the scale of risks and the opportunities for escape of transgenes and their effects. Within a laboratory genetic material is not interacting with environmental influences beyond the control of laboratory procedures and facilities. By drawing the line at the laboratory door we would place the scale of risk many orders of magnitude lower than a situation of routine field trials. This is because with laboratory containment, the pathways for the movement of genetic material are either removed or severely restricted in comparison with field trials or commercial release.

Genetic Free Markets?

Some people argue that if HGT happens, then there is no need to worry about the insertion of genes across species barriers √ because it is happening all the time (e.g. between plants and bacteria). If there was indeed a genetic free market (and no barriers to the free flow of genetic material) then there would be very little genetic diversity in the world √ and after 400 million years of free flow of genes, quite probably only a single species on Earth. The issue is not the crossing of the species barrier as such, but rather the bypassing of biological control mechanisms that have evolved with the purpose of preventing calamity. Natural HGT happens within certain limits that are not fully understood. Insertion of transgenes across species barriers by-passes these natural limits.

Molecular Ecology

Those who understand ecology have little difficulty comprehending the way that feedback loops work and the way that myriads of interactions are the stuff of life itself. Those who have not studied ecology or who do not think in an holistic fashion may have reason to believe that there is not a molecular ecosystem to disrupt. This is essentially the fundamental philosophical difference between scientists on different sides of the GMO divide. Those who acknowledge and understand the universe as an interconnected whole have no difficulty recognising and documenting the risks of GMO technology.

See also: ORGANIC NZ ENDS

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