|27 February 2019
THIRD WORLD NETWORK BIOSAFETY INFORMATION SERVICE
Dear Friends and Colleagues
Genetic Engineering Technique Causes Unexpected Genome Damage
The bacterium Agrobacterium tumefaciens has been the workhorse in plant genetic engineering. Using a combination of new techniques, a recent study has now obtained a clearer picture of what happens when genes are spliced into the genomes of plants and animals.
The study found that inserting new genes into a plant using this bacterium as a shuttle creates major unintended effects in the genome. In addition to identifying multiple complete and partial genetically modified gene insertions, numerous large rearrangements of the plant genome were detected. Furthermore, epigenetic (gene regulatory) changes were also identified that could have a wide range of effects, from the silencing of the introduced GM gene to alterations in function of multiple host gene systems. These effects are likely to result in substantial alterations in overall gene expression and consequent changes in the biochemistry, composition and growth characteristics of the GM plants.
Noteworthy is that the findings won’t enable genetic engineers to prevent DNA damage in the first place, but only to more easily spot the lines in which they have caused the most unintended damage. In addition, increased efficiency in weeding out those GM plants with the most off-target genetic and/or epigenetic damage will not ensure good crop performance and food safety. This is because even small changes in gene function can bring about unpredictable major alterations in the biochemistry and hence composition of plants. Thus, generic testing for unexpected toxic effects from the GM process (both old-style transgenic and newer gene editing) is still needed.
With best wishes,
Third World Network
131 Jalan Macalister
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