As a short addition to my previous two articles on Gene editing and GMOs in New Zealand, readers might like to read the arguments presented in an article just published, Moving Beyond the GM Debate, by Ottoline Leyser. The article is one of two Perspectives in the PLoS Genetics’ The Promise of Plant Translational Research collection and is open-access (i.e. free to be read by anyone).
Readers should note that the article is mostly about recombinant plants, where new genes are added. It’s common for GM (genetic modification) to be defined in terms of adding new genetic material, as the author writes “GM involves introducing a gene directly into the genome of an organism.” New Zealand legislation doesn’t do this but the points she raises are worth thinking about, whether you agree with them or not.
Gene editing, the subject of my previous articles, does not introduce new genes or other genetic material into the plant. They create new variants at targeted positions in the genome by nicking the DNA; when the plant’s DNA repair systems kick in and repair the nick, some of the time the error correction will be faulty and create a new variant at the position. This is similar to how variants are caused by UV light. (A light take on this can be found in my first part of these series.)
In the New Zealand legislation, techniques that use mutagenesis to create new variants (mutants) of plants are considered not to create GMOs. The ZFN-1 and TALEN gene editing techniques are targeted mutagenesis techniques, they create variants at targeted positions. A recent court ruling in New Zealand overturned opinion that these techniques did not create GMOs. This ruling (PDF file, see clause 16) noted other jurisdictions consider these not to create GMOs.
New Zealand’s ruling is then at odds with these other jurisdictions. Leyser noted this in a more general way and suggested testing should be based on the traits of the organism, not how they were made (as they are in NZ) –
This confusion between the effects of a new trait and the method by which it has been introduced is enshrined in the way new crops are licensed for commercial release in many countries.
In my opinion, there is therefore no justification for considering GM vs non-GM herbicide tolerant crops differently. Their assessment, from a regulatory viewpoint and in terms of their environmental impact, should be based on the distinctive trait they carry.
These new tools provide exciting and much needed opportunities for crop genetic improvement, but in my view they also demand a more sensible licensing system that assesses all new crops based on the traits they carry rather than on the method by which they were introduced.
As I noted in my previous part, New Zealand’s legislation is based on the techniques that create the plants rather than what is created. Her suggestion of that testing should be based on traits irrespective of the how the new plant was created is similar to my own initial thoughts. When I read the GMO clauses of the HSNO Act my first thoughts were ‘surely this wants to be based on the traits of the organisms made, how they are made isn’t especially relevant.’
It’s probably useful here to explain what I did in my previous part, as I suspect some readers might have been confused by my approach. One criticism of scientists speaking out on a subject is that they sometimes don’t take what is offered to them seriously, dismissing it out of hand. You could respond by saying that basis of the GMO clauses in the HSNO Act is silly and should be based on the traits of the organisms. Rather than do that, I choose to instead look at what is currently there, whether I agreed with it or not, and work from that. My opinion was that the GMO clauses in the HSNO Act had, to my reading, major problems. I thought the GMO clauses of the HSNO Act were due to be retired and work should begin on what would follow it.
Feel free to share your thoughts on Ottoline Leyser’s article in the comments below.
Reading Ottoline Leyser’s article, I realise I missed another way to illustrating consumers consuming variants in my first part. There, in Footnote 7, I briefly mention ‘jumping genes’ or transposons. Transposons can move about a genome. When they land in or near a gene they can affect the function of the gene they landed within or near. These variants are found in commonly eaten food. As Ottoline Leyser put it –
Many viruses can insert their genomes into that of their host as a normal part of their life cycle. These viral sequences, and many related genetic elements, such as retroposons, accumulate over evolutionary time and can continue to move about the genomes of their hosts, creating new DNA insertion sites. Thus, every conventionally bred rice crispy or cornflake you had for breakfast probably differs from every other one by the insertion of a piece of DNA at an unknown site in its genome.
1. Leyser O (2014) Moving beyond the GM Debate. PLoS Biol 12(6): e1001887. doi:10.1371/journal.pbio.1001887
2. Copied from clause 16 (page 7) of the ruling:
(a) As at 2012 the United States’ Department of Agriculture informed crop companies that the techniques lay outside the scope of current legislation and did not require regulatory oversight.
(b) As at 2012 Australia’s Office of the Gene Technology Regulator had not publically given guidance on whether the techniques result in genetically modified organisms. However it was considered likely that they would not be regarded as genetically modified organisms.
(c) As at 2011 the relevant authority in Germany had stated that it did not consider organisms using ZFN-1 to be genetically modified organisms if the mutagenesis reaction was mediated by protein or mRNA.
(d) The consensus at a 2012 international working group was that it was very likely that organisms from the use of ZFN-1 would be classed as not genetically modified organisms, and that such organisms cannot be distinguished from crops derived through mutagenesis induced by chemicals or irradiation and should be regulated in the same way.
3. While on the face of it this might often seem a valid criticism, I suspect one issue is that by going straight to the final point, without explaining how scientists got to their position, non-scientists can be left feeling that what they’ve offered has not be considered at all.
Other articles in Code for life: