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Sent: 03 June 2002 09:50
Subject: 2: Gene flow and genetic diversity
[Participants are reminded
i) to introduce themselves briefly in their first first posting to the conference
ii) that people posting messages are assumed to be speaking on their own behalf and not on behalf of their employers. Rule 5 of the Forum states "5. Attribution: Regardless of whether they identify the entity by whom they are employed, Participants are assumed to be speaking in their personal capacity unless they explicitly state that their contribution represents the views of their organization. For this reason, Participants should not quote the postings of other Participants as representing the views of the organizations to which those other Participants belong."........Moderator]
The already existing non-GM populations in the crop, forestry, animal and fishery sectors are the sink of economically and genetically important traits,which have to be preserved for future research and breeding programs. These valuable genetic resources have to be preserved in their respective pure nature not only for the future usage but also to preserve the genetic diversity.
In the mean time, irrespective of the argument of whether GM food will feed and alleviate the poverty in developing countries, the fact is that the knowledge explosion that has taken place in the field of biotechnology has brought genetic modification across the species into reality.
The million dollar question is whether gene flow from GM to non-GM populations will affect genetic diversity and pollute its purity? The GM organisms should be studied not as a whole by case by case. In all cases, it is always good to do studies on the behaviour of GM organisms in the long term interest before releasing them into the environment. And also it always advisable to set up GM-free zones around the GM populations to prevent gene flow between GM and non-GM populations.
GM crops could be released for commercial production in the case if
1) it is 100% self pollinating and it is not crossing with its ancestors
2) the risk of gene pollution is worth taking when compared to the hazards caused by the excessive usage of chemicals in agriculture.
M.Sc- in Biotechnology
Postgraduate Institute of Agriculture,
University of Peradeniya,
muhunthan_r (at) yahoo.com
Sent: 03 June 2002 10:22
Subject: 3: Re: Fundamental considerations in hazard identification of GMOs
Further to the inputs of Dr. Suzanne Wuerthele (message 1, 31 May) recombinant DNA (rDNA) technology is isolating a gene and inserting it into the DNA of another organism. Also called genetic engineering, gene splicing, genetic modification. Genetic modification should not be confused with biotechnology. Just as genetic modification does not refer to conventional plant breeding.
Education is essential for the public to better understand this misunderstood differences. Failing to address the potential risks would be a betrayal of public trust. Uncertainty of the current rDNA crops and food is of substantial economic concern as the conflict affects the entire field of plant biotechnology. The careless and continous release would be insidious and irreversable to developing more abundant and nutritious foods in a more enviromentally sound manner.
Javier M. Claparols
Ecological Society of the Philippines
jmc1 (at) mozcom.com
Sent: 03 June 2002 11:40
Subject: 4: GM crops - exotic genes/species
This is from Bert Uijtewaal. I am active as a product safety manager for Aventis CropScience where my responsability is to support the global safety evaluation of GM products. I got my PhD degree in Plant Breeding and BioTech. I support a careful approach to release the new plant products developed with the help of modern biotechnology. The necessary safety evaluation should be done on a case by case basis.
I know from my own experience that characteristics like 'stability of expression', 'unexpected side effects', 'expression in different genetic backgrounds', ' interaction with soil organisms', 'effects on persistence' etc are topics that are studied for at least 3-5 years during an intensive selection program. The costs related to the development and registration of such a product are so high that a company can not afford to develop a product that will not last. This might have been different 10 years ago, but is certainly not the case now.
The more we get to know about biotechnology, the more we learn about conventional breeding. It seems that also in these products chromosomal rearrangements occur and outcrossing always happened; we only missed the easy to score markers. Working with exotic genes is also not specific for biotechnology. At the moment you release a crop in an area where this did not grow naturally you introduce an enormous amount of exotic genes that can and will outcross to wild relatives. We never bothered about this and even learned over time that the impact of this is limited. It is the introduced new species itself that can be a disaster for regions where it was not known. This has however nothing to do with biotech or with conventional breeding.
Bert.Uijtewaal (at) aventis.com
Sent: 03 June 2002 14:22
Subject: 5: Re: Fundamental considerations in hazard identification of GMOs
I wish to make some comments on the message of Suzanne Wuerthele (message 1, 31 May). [Message 1 contained seven paragraphs and these comments are organised here by paragraph. Definitions of some technical terms used here are provided at the end of the message...Moderator]
Paragraph 1: - Novel traits, not novel methods of producing traits, are what should be of concern.
- Virtually all eukaryotes contain DNA from organisms with which they cannot
breed (e.g., mitochondrial DNA, relictual T-DNA in Nicotiana). This is
hardly unique to GMOs.
- Organisms produced by conventional breeding can, and do, transfer 'exotic' genes, for the simple reason that nearly all major crops are grown outside their native geographic range.
- Conventional breeding does not 'merely' rearrange existing native genes, either. Mutation (induced and spontaneous), combined with intense artificial selection, are the drivers of conventional breeding.
Paragraph 3: - Agrobacterium has been moving genes across wide phyletic divisions for millions of years. Horizontal gene transfer is not a human invention, and is not limited to viruses in nature.
- Surely the argument is not that transgenes are *uniquely* unstable --
there is a vast literature on paramutation, transposition, etc. to refute
- Transgenes may, or may not, have altered transcriptional regulation. No sweeping statement about transgene stability or regulation can be made truthfully; each transgene and transgenic event must be characterized separately.
- The idea that mutations are a 'modern' breeding technology is laughable. Look at teosinte and maize if there is any doubt about the longstanding importance of mutation in agricultural breeding.
- Regarding the statement: "Transgenes are multiplied in number or are
accompanied by promoters so that the products for which they code are
expressed in high concentration.", They may, or may not, be. No such
generalization is possible.
- There is no such thing as a 'promoter gene.'
- It is wrong to say that "Transgene insertions create frameshift mutations
which may alter host DNA function and stability.". Transgene insertion may
cause *insertional* mutations that abolish gene function. If the claim is
that this leads to instability as well, please provide some evidence of
- It is wrong to say that "Ideally transgenes are inserted into "quiescent" sections of the host genome, previously assumed to be non-coding regions.". Ideally, transgenes are inserted into euchromatin, which is transcriptionally active. 'Quiescent' regions of the genome are generally heterochromatic, and poor targets for transgenes whose expression is needed to produce the desired trait.
- mutation=DNA damage, and mutation is the ultimate source of genetic variation upon which all evolutionary mechanisms act.
Paragraph 7: Regarding "When rDNA techniques employ promoters and other genetic elements derived from viruses there is a potential for these elements to combine with DNA from host pathogens to create novel diseases. While this phenomenon has been documented in conventional plants and animals..", could an example from plants be provided
College of Forest Resources & Department of Botany
University of Washington,
toby (at) u.washington.edu
[Euchromatin: Chromosomal material that is stained less intensely by certain
dyes. Thought to be the chromosomal domains which are gene-rich...
Eukaryote: One of the two major evolutionary clades, characterized by having the nucleus enclosed by a membrane, and possessing chromosomes that undergo mitosis and meiosis. Eukaryotic organisms include animals, plants, fungi and some algae.
Heterochromatin: Regions of chromosomes that remain contracted during interphase and therefore stain more intensely in cytological preparations. These regions have a high content of repetitive DNA, and a low content of genes; thus they are for the most part genetically inactive.
Paramutation: A naturally occuring gene silencing phenomenon.
T-DNA: The DNA segment of the Ti plasmid, present in pathogenic Agrobacterium tumefaciens, that is transferred to plant cells and inserted into the plant's DNA as part of the infection process.
Transposition: The process whereby a transposon (A DNA element that can move from one location in the genome to another) or insertion sequence inserts itself into a new site on the same or another DNA molecule.
Further information on such terms can be got from the FAO Biotechnology Glossary, available at http://www.fao.org/DOCREP/004/Y2775E/Y2775E00.HTM or, as a searchable database, at http://www.fao.org/biotech/index_glossary.asp ......Moderator]
Sent: 03 June 2002 14:31
Subject: 6: GM crops in Africa
My name is Jane Morris, and I am Director of the African Centre for Gene Technologies (ACGT) based in South Africa.
Having been involved with biosafety issues in Africa for a number of years,
it is clear that research is needed in order to enable scientists and
regulators to make informed judgements concerning the safety of GMOs. Too
often the only information available is derived from experiments carried out
in the developed world. For instance:
- Insufficient information is available about the potential for crops to cross-pollinate with African wild relatives
- Not enough is known about the insect pollinators in Africa and their habits (e.g., can recommendations on separation distances gathered, for example, from knowledge of the range of bees in the United States be translated into similar recommendations for field trials in Africa?)
There is huge potential for multidisciplinary research projects to gather information on this type of issue, but as is usual in the African context, the funding is scarce! It would be encouraging if the companies who are developing GMOs in the First World would give attention to the need to fund this type of research in the developing world. Otherwise, there is a danger that the safe implementation of GM technology in Africa will be impeded in future.
E Jane Morris PhD
African Centre for Gene Technologies
P O Box 75011
Tel: +27 12 841 2642
Fax: +27 12 841 3105
Cellular: +27 82 566 2210
e-mail: jmorris (at) csir.co.za
Sent: 03 June 2002 14:54
Subject: 7: Personal view on GM crop gene flow
I am Dr. Swapan Datta, plant biotechnologist at the International Rice Research Institute, working on rice improvement using haploid and transgenic breeding approaches.My personal view on gene flow is as following:
Gene flow is a natural phenomenon that happens in nature, more in compatible outcrossing species and less in self-pollinating species. Transgenes per se should be understood well from the scientific point of view, stability, products and its possible interaction with the environment. Once the gene is known as safe and characterized, there should not be much concerns regarding its possible flow to the environment. In such case, nothing could go wrong with the transgene flow compared to naturally occurring gene flow. Any deviation reflected in the phenotype or based on molecular characterization can easily be discarded which is a normal practice followed by all plant breeders. Transgenic plants process the inherited transgene and, in most cases, produce a product (e.g. protein) and there is a possible reflection in the phenotype - either for plant protection, yield or nutrition improvement. This process takes time until a homozygous material is developed and eventually farmers get an option to use it. Scientists take care in developing such products before transferring the materials to the recipient farmers through regulatory/biosafety processing. It is a great opportunity to explore this visible science of plant breeding while scientists can monitor the gene expression and understand its better use for improvement of agricultural crops.
S.DATTA (at) CGIAR.ORG
Sent: 03 June 2002 15:11
Subject: 8: Re: GM crops - exotic genes/species
As Dr. Bert Uijtewaal mentioned (message 4, 3 June), introduction of a conventional breed also could be a disaster for the already existing species. A good example is some exotic freshwater fish species brought into Sri Lanka as ornamental varieties that are posing immense threat to some already existing local varieties. It shows that the ecological balance of a region could be tilted by the introduction of a conventional breed also. The GM organisms should be analysed case by case (as I said in my previous posting (message 2, 3 June), also Dr. Bert Uijtewaal expressed a similar view).
As far as crops are concerned, many of them have been domesticated by man long ago and the plant breeders have enough data about their behaviour in the ecosystem, i.e., how they cross and breed. Unlike crops, on forest tree species no extensive studies are being carried out and the available data are not substantial. Therefore, we have to do extensive studies on them before any genetic modification is done.
M.Sc- in Biotechnology
Postgraduate Institute of Agriculture,
University of Peradeniya,
muhunthan_r (at) yahoo.com
Sent: 03 June 2002 15:24
Subject: 9: Re: GM crops - exotic genes/species
My name is André Dusi, working at Embrapa Vegetables, Brasília, Brazil. I'm a plant virologist and work on a project on GM virus resistant potatoes.
I want to make just a brief comment on the statment by Bert Uijtewaal (message 4, 3 June):"It is the introduced new species itself that can be a disaster for regions where it was not known.". I completely agree with that statement. In Brazil (and also in other countries), ecological problems related to the introduction of new conventional species (crops) can be easily identified. Destruction of continuous areas to grow pastures, soybean or maize may cause potentially more damage to the environment then some GM crops.
Of course we have to be on the safe side and analyse case by case, but with an open mind for the benefits of introducion of new traits into a crop.
André Nepomuceno Dusi, Ph. D.
CP218, Brasilia, DF
dusi (at) cnph.embrapa.br