New Zealand genetic engineer Tony Conner claims to have developed a new genetic engineering technique which by using vectors based on the DNA of the target crop does not involve the transfer of foreign DNA (such as the widely used Cauliflower Mosaic Virus).
Conner claims that plants produced using this technique "are, by definition, not transgenic", despite the fact that they have been genetically engineered. He says this would, in the case of some countries, move them outside the regulations intended to control the release of GM plants and that "this means the compliance costs involved in gaining approval for commercial use are minimised." he also says it would make them hard to detect as GM plants.
But as former genetic engineer, Dr Elvira Dommisse, points out in her response below, Conner's attempt to dodge the consequences of the GM definition does not get round key safety issues arising from genetic engineering.
Widely used, but transgenic science still up for debate
RURAL NEWS, 23 Aug 05, p. 24
In the article "New technique challenges GM definition" (12 July) Tony Conner says "We're only using genes which are already available to traditional plant breeders. But we can transfer those genes responsible for a particular characteristic into a new plant very precisely, in one step."
Firstly, the genes are not "precisely" transferred, ending up anywhere in the recipient plant's DNA. Secondly, the insertion of these genes is not problem-free.
Researchers (1) have documented that a large fraction of even apparently simple (trans)gene insertion events result in large-scale DNA rearrangement or deletion and superfluous DNA insertion (2). This occurs when transgenic DNA is inserted into plant cell DNA using the bacterial vector Agrobacterium.
These authors (1) speculate that widespread use of transgenic crops carrying insertion-site mutations of this magnitude could lead to harmful consequences. Mutations such as these would almost certainly pass unnoticed through both the molecular and phenotypic characterization stages of the current regulatory systems of both the EU and the US.
These scientists are but some of many whose concerns about GM techniques have been aired. Not all scientists share Tony Conner's enthusiasm.
He also says, "It is difficult to test for GM in these plants because all the genetic (DNA) material is already there. So it compromises the concept of GM testing."
How then does he determine that his potatoes have in fact been genetically modified?
Elvira Dommisse (Dr)
1. Wilson, A., Latham, J. & Steinbrecher, R. Genome Scrambling-Myth or Reality? Transformation-induced Mutations in Transgenic Crop Plants. (Econexus, Brighton, UK, 2004). http://www.econexus.info
2. Forsbach, A., Schubert, D., Lechtenberg, B., Gils, M. & Schmidt, R. Plant Mol. Biol. 52, 161-176 (2003).