Under intense industry lobbying, regulators around the world are being persuaded to by-pass safety testing of gene-edited foods [1]. The main argument for ignoring such a basic safeguard of human health is that the genome changes inflicted "could happen in Nature".
This claim is based on a century-old theory that genetic mutations are 'normal', ongoing, random mistakes arising in the inherited "factors or elements"* in cells during reproduction, leading to natural evolution.
* The 1964 Oxford English Dictionary's definition of a 'gene' is "One of the factors or elements of which a germ cell contains a pair transmitted each from one parent"
Throughout the subsequent discovery of chromosomes, DNA, epigenetic modifications to the expression of DNA, and gene-mobility, -families, -linkages, -duplications and -networks, scientists have been unable to let go of the age-old dogma.
* The 1964 Oxford English Dictionary's definition of a 'gene' is "One of the factors or elements of which a germ cell contains a pair transmitted each from one parent"
Throughout the subsequent discovery of chromosomes, DNA, epigenetic modifications to the expression of DNA, and gene-mobility, -families, -linkages, -duplications and -networks, scientists have been unable to let go of the age-old dogma.
Science has been showing for some time that gene mutation isn't a random or normal occurrence: living cells heal themselves. In the case of DNA-replication, a refined mismatch-repair system makes sure essential genes don't mutate while genes in which diversity could be useful may be allowed to change.
Note that, even after the DNA wreckage caused by irradiation or toxic chemical mutagens, which crop breeders have been using for decades to develop 'improved' crop plants, the core genes don't mutate.
Gene-editing devices, such as CRISPR [2] "alter the genome of target organisms in a way that is extremely difficult or impossible to achieve using conventional breeding techniques" (Kawall). Such changes don't happen in Nature because they'd be corrected.
Neither could the CRISPR-induced, simultaneous, identical mutation of multiple gene copies in a single genome happen in Nature.
Neither could the CRISPR-induced mutation of several different genes at the same time, dubbed "multiplexing", happen in Nature.
Single-gene knock-out, a favourite use of gene-editing but highly unbalancing for the organism, is unlikely to happen in Nature [3].
"A general assumption that (first-generation gene-editing) alterations are identical to naturally occurring mutations or induced mutations, and are therefore just as safe, cannot be made." (our emphasis, Kawall)
The notion that a gene-edit is just one small tweak in a very small fragment of DNA is belied by the fact that, in practice, such a minimal change often isn't very useful: about half of the market-oriented gene-edited plants are a result of multiplexing.
No matter how precise the edit or how small the change in DNA, the actual end-effect will depend on what the gene naturally interacts with, it's entire genetic background, its epigenetic status, and the structure of its protein scaffold: an edited gene is a disconnected gene which can't be relied on to do what's expected of it by humans or to do what's needed by the plant.
Add to this the discovery that epigenomic features (and therefore associated environmental interactions) [4], play an important part in determining allowable, natural, mutations.
Gene-editing devices by-pass the cell's natural gene protection, natural internal genome interactions, and natural environment/gene connections essential to healthy, resilient plants.
There's also a well-established precision problem with gene-editing [5]. "Many publications have already shown that CRISPR/Cas induces off-target and unintended on-target effects, in addition to unintended frameshift mutations that can generate ... new gene products ". It has also been shown that foreign DNA fragments from the editing procedure can be unintentionally integrated at the target site or elsewhere in the genome [6]. "Moreover the majority of (first generation gene-editing) applications still rely on ... classic (or other) transformation techniques to deliver (the gene editing tool) which are known to induce unintended alterations." (Kawall)
If you're getting the impression that plant cells are really more intelligent and self-reliant than humans, you may be right. Interfering with that self-preserving intelligence of crop plants could wipe out our food supply.
Your Westminster representative in our gung-ho pro-GM government needs to know gene-editing doesn't happen in nature.
Background
[1] GENE-EDITED CROPS: CONTROLLING, UNJUSTIFIABLE AND UNNECESSARY - July 2022
[2] CRISPR/Cas9 GENE EDITING - March 2016
[3] 'KNOCKING-OUT' A GENE CREATES A NEW ONE - July 2019
[4] CRISPR'S EPIGENETIC SCARS - August 2021
[5] THE PRECISION PROBLEM IN GENOME EDITING - August 2021
[6] THE PROMISE OF GENE-EDITED MUSHROOMS - July 2022
SOURCES:
Note that, even after the DNA wreckage caused by irradiation or toxic chemical mutagens, which crop breeders have been using for decades to develop 'improved' crop plants, the core genes don't mutate.
Gene-editing devices, such as CRISPR [2] "alter the genome of target organisms in a way that is extremely difficult or impossible to achieve using conventional breeding techniques" (Kawall). Such changes don't happen in Nature because they'd be corrected.
Neither could the CRISPR-induced, simultaneous, identical mutation of multiple gene copies in a single genome happen in Nature.
Neither could the CRISPR-induced mutation of several different genes at the same time, dubbed "multiplexing", happen in Nature.
Single-gene knock-out, a favourite use of gene-editing but highly unbalancing for the organism, is unlikely to happen in Nature [3].
"A general assumption that (first-generation gene-editing) alterations are identical to naturally occurring mutations or induced mutations, and are therefore just as safe, cannot be made." (our emphasis, Kawall)
The notion that a gene-edit is just one small tweak in a very small fragment of DNA is belied by the fact that, in practice, such a minimal change often isn't very useful: about half of the market-oriented gene-edited plants are a result of multiplexing.
No matter how precise the edit or how small the change in DNA, the actual end-effect will depend on what the gene naturally interacts with, it's entire genetic background, its epigenetic status, and the structure of its protein scaffold: an edited gene is a disconnected gene which can't be relied on to do what's expected of it by humans or to do what's needed by the plant.
Add to this the discovery that epigenomic features (and therefore associated environmental interactions) [4], play an important part in determining allowable, natural, mutations.
Gene-editing devices by-pass the cell's natural gene protection, natural internal genome interactions, and natural environment/gene connections essential to healthy, resilient plants.
There's also a well-established precision problem with gene-editing [5]. "Many publications have already shown that CRISPR/Cas induces off-target and unintended on-target effects, in addition to unintended frameshift mutations that can generate ... new gene products ". It has also been shown that foreign DNA fragments from the editing procedure can be unintentionally integrated at the target site or elsewhere in the genome [6]. "Moreover the majority of (first generation gene-editing) applications still rely on ... classic (or other) transformation techniques to deliver (the gene editing tool) which are known to induce unintended alterations." (Kawall)
OUR COMMENT
If you're getting the impression that plant cells are really more intelligent and self-reliant than humans, you may be right. Interfering with that self-preserving intelligence of crop plants could wipe out our food supply.
Your Westminster representative in our gung-ho pro-GM government needs to know gene-editing doesn't happen in nature.
Background
[1] GENE-EDITED CROPS: CONTROLLING, UNJUSTIFIABLE AND UNNECESSARY - July 2022
[2] CRISPR/Cas9 GENE EDITING - March 2016
[3] 'KNOCKING-OUT' A GENE CREATES A NEW ONE - July 2019
[4] CRISPR'S EPIGENETIC SCARS - August 2021
[5] THE PRECISION PROBLEM IN GENOME EDITING - August 2021
[6] THE PROMISE OF GENE-EDITED MUSHROOMS - July 2022
SOURCES:
- Katherina Kawall, 2021, The Generic Risks and the Potential of SDN-1 Applications in Crop Plants, Plants 10
- J. Grey Monroe, et al., January 2022, Mutation bias reflects natural selection in Arabidopsis thaliana, Nature
- U.C. Davis, Study challenges evolutionary theory that DNA mutations are random, phy.org, 12.01.22
- New study highlights gulf between gene editing and conventional breeding, GM Watch, 20.01.22
Image Creative Commons
No comments:
Post a Comment
Thanks for your comment. All comments are moderated before they are published.