In October 2019, the US Food and Drug Administration (FDA) gave the green light for GM cottonseed to be sold as food.
Cottonseed isn't a familiar food item. This is because cotton plants contain 'gossypol', a rather nasty toxin.
Showing posts with label RNA interference. Show all posts
Showing posts with label RNA interference. Show all posts
Edible GM cottonseed
January 2020
In October 2019, the US Food and Drug Administration (FDA) gave the green light for GM cottonseed to be sold as food.
Cottonseed isn't a familiar food item. This is because cotton plants contain 'gossypol', a rather nasty toxin.
In October 2019, the US Food and Drug Administration (FDA) gave the green light for GM cottonseed to be sold as food.
Cottonseed isn't a familiar food item. This is because cotton plants contain 'gossypol', a rather nasty toxin.
GM in sewage
One concern about GM crops which European regulators have always taken seriously, is the possibility of the horizontal gene transfer of artificial antibiotic-resistance genes from GM food plants into strains of bacteria which cause human and livestock disease.
Antibiotic-resistance has been described as medicine's climate change: a modern day plague [1].
Historically, most commercial GM crops incorporated antibiotic-resistance genes as part of their development procedure, and many 'newer' GM crops on the market are little more than stacked versions of the old. Although there's been a shift to the use of other marker genes in GM crops for the US market, antibiotic-resistance genes continue to be present especially in GM consumed in 'lower resourced countries'.
RNAi doesn't just disappear
October 2019
After ten years of development, the US Environmental Protection Agency (EPA) quietly approved the first 'SmartStax Pro' GM maize with an RNA interference gene to kill a major corn pest, western corn root worm [1].
The artificial RNA produced by this technique, 'RNAi', is designed to match precisely the active RNA produced by a vital gene specific to the pest. By high-jacking the pest's own mechanism for silencing that gene, RNAi destroys the expression of the gene and the pest dies.
*Note. RNAi crop sprays are also in use, but are less effective at killing pests than the GM plant version which the pests consume.
A few months after the EPA ushered in this first GM maize with RNAi, a study was published which raised doubts about the claimed specificity of such insecticides. Using the honey bee as a model, the scientists "identified 101 insecticidal RNAs sharing high sequence similarity with genes in honey bees (indicating a huge scope for off-target gene silencing). "Of concern is that gene groups active during vital honey bee embryo formation and development had a disproportionately high sequence similiarity with all these RNAi pesticides: the scope for defective bees seems very real" [2].
After ten years of development, the US Environmental Protection Agency (EPA) quietly approved the first 'SmartStax Pro' GM maize with an RNA interference gene to kill a major corn pest, western corn root worm [1].
The artificial RNA produced by this technique, 'RNAi', is designed to match precisely the active RNA produced by a vital gene specific to the pest. By high-jacking the pest's own mechanism for silencing that gene, RNAi destroys the expression of the gene and the pest dies.
*Note. RNAi crop sprays are also in use, but are less effective at killing pests than the GM plant version which the pests consume.
A few months after the EPA ushered in this first GM maize with RNAi, a study was published which raised doubts about the claimed specificity of such insecticides. Using the honey bee as a model, the scientists "identified 101 insecticidal RNAs sharing high sequence similarity with genes in honey bees (indicating a huge scope for off-target gene silencing). "Of concern is that gene groups active during vital honey bee embryo formation and development had a disproportionately high sequence similiarity with all these RNAi pesticides: the scope for defective bees seems very real" [2].
RNAi has been quietly ushered in
September 2019
While all the recent biotech limelight has been on gene
editing, especially CRISPR, another older GM crop 'improvement' technique has
continued to creep quietly up on us.
RNA interference, 'RNAi', which artificially alters gene
expression, is still with us [1].
Note. RNA interference is also known as double-stranded RNA, 'dsRNA'.
Although at the time no one actually knew why, the very
first commercial, fresh GMO venture, the FlavrSavr tomato, ripened abnormally
slowly due to RNA interference. GM
papaya with RNAi-based viral resistance has been on some markets for a long
time. Arctic apples which don't turn
brown when sliced thanks to RNAi are working their way into US shops. GM-Free Scotland readers will be aware of
Pandora's Potatoes with RNA interference to stop their bruises showing (even
although the damage is still there), to stop them turning brown when fried
(even although they taste like cardboard), to stop them producing the
carcinogen, acrylamide (even although potatoes don't produce enough
acrylamide to cause cancer), and to encourage potato growing in areas with
a high risk of late blight (even if other crops could be better grown there)
[2].
Many others are under development, but the blockbuster
everyone's been waiting for is a commodity crop with its very own RNAi-based
insecticide. This is a radical departure
from what's gone before because the artificial RNAi in the GM plant will be
designed to silence gene expression in another organism in its
environment.
Single nucleic acid editing
July 2019
The latest refinement in gene editing tools is nucleic acid
editing: this alters a single pair of the many nucleic acids which make up the
double strand of DNA*, and promises deft improvements in crop and livestock
genomes.
RNAi fantasy
February 2018
Some 40% of pollinator species, including butterflies and bees, are facing extinction.
Climate change is, of course, taking its toll as wild animals find their life-cycles out of step with the plants they depend on. More has been made, however, of the toll exacted by neonicotinoid insecticides ('neonics').
Now, the largest ever field study of the effects of neonics on bees has, indeed, confirmed the negative impact. It also revealed the extent of contamination of wild plants. This was backed up by second study published the same day which reported that wildflowers are the bees' main source of exposure to the insecticides.
Some 40% of pollinator species, including butterflies and bees, are facing extinction.
Climate change is, of course, taking its toll as wild animals find their life-cycles out of step with the plants they depend on. More has been made, however, of the toll exacted by neonicotinoid insecticides ('neonics').
Now, the largest ever field study of the effects of neonics on bees has, indeed, confirmed the negative impact. It also revealed the extent of contamination of wild plants. This was backed up by second study published the same day which reported that wildflowers are the bees' main source of exposure to the insecticides.
A GM cure for toxic maize
July 2017
Each year, some 16 million tons of maize are lost globally to contamination by 'aflatoxins' after infection by some species of Aspergillus fungus.
In the US alone, wastage due to aflatoxins is estimated to cost agriculture $270 million per annum. Added to this is the expense of essential regulation for safety, because some forms of aflatoxin are the most potent toxins on the planet.
The substance produced by Aspergillus isn't, in itself, harmful. Ironically, when it reaches the liver, the main organ of detoxification, aflatoxins are transformed into derivatives which are toxic at levels of very few parts per billion. At very high doses, aflatoxins can cause acute liver damage and death. More usually however, their effects are chronic. They have been linked to birth defects, impaired immune system and, in the young, stunted growth.
Aflatoxins also have the sinister ability to target DNA and, in particular, attack a specific gene which protects against cancer. The result is liver cancer.
Each year, some 16 million tons of maize are lost globally to contamination by 'aflatoxins' after infection by some species of Aspergillus fungus.
In the US alone, wastage due to aflatoxins is estimated to cost agriculture $270 million per annum. Added to this is the expense of essential regulation for safety, because some forms of aflatoxin are the most potent toxins on the planet.
The substance produced by Aspergillus isn't, in itself, harmful. Ironically, when it reaches the liver, the main organ of detoxification, aflatoxins are transformed into derivatives which are toxic at levels of very few parts per billion. At very high doses, aflatoxins can cause acute liver damage and death. More usually however, their effects are chronic. They have been linked to birth defects, impaired immune system and, in the young, stunted growth.
Aflatoxins also have the sinister ability to target DNA and, in particular, attack a specific gene which protects against cancer. The result is liver cancer.
Pesticides' catastrophic impacts
May 2017
In March this year, the United Nation (UN) special rapporteurs on the right to food and on toxics presented a scathing report on pesticides.
It pointed to the "catastrophic impacts (of pesticides) on the environment, human health and society as a whole", including an estimated 200,000 deaths a year from acute poisoning alone, plus untold suffering from chronic pesticide exposure now linked to "cancer, Alzheimer's and Parkinson's disease, hormone disruption, developmental disorders and sterility".
In March this year, the United Nation (UN) special rapporteurs on the right to food and on toxics presented a scathing report on pesticides.
It pointed to the "catastrophic impacts (of pesticides) on the environment, human health and society as a whole", including an estimated 200,000 deaths a year from acute poisoning alone, plus untold suffering from chronic pesticide exposure now linked to "cancer, Alzheimer's and Parkinson's disease, hormone disruption, developmental disorders and sterility".
The billion dollar bug
May 2017
In 1868 western corn rootworm (WCR) was observed in Kansas to be a harmless chewing insect from Central America found in low populations on the Western Great Plains.
*Note the naturally low numbers, and the suggestion that these beetles can naturally travel long distances.
When centre-pivot irrigation with it's quarter mile watering radius (so efficient it's now sucking the plains dry) was introduced in the 1950s, maize monoculture madness gripped American farmers. Across the land, prairies were converted to horizon-scale corn fields.
To the WCR, which fed exclusively on corn and lay their eggs there, this became an 80-million acre banquet-plus-nursery.
In 1868 western corn rootworm (WCR) was observed in Kansas to be a harmless chewing insect from Central America found in low populations on the Western Great Plains.
*Note the naturally low numbers, and the suggestion that these beetles can naturally travel long distances.
When centre-pivot irrigation with it's quarter mile watering radius (so efficient it's now sucking the plains dry) was introduced in the 1950s, maize monoculture madness gripped American farmers. Across the land, prairies were converted to horizon-scale corn fields.
To the WCR, which fed exclusively on corn and lay their eggs there, this became an 80-million acre banquet-plus-nursery.
CRISPR/Cas9 gene editing
March 2016
GM is changing. Forget shooting the genome to bits with a
micro-blunderbuss in the hope that the novel DNA-bullets lodge somewhere
useful. Now genetic engineers have a
simple, inexpensive and remarkably effective method for making specific DNA
modifications.
The latest from biotech is 'CRISPR/Cas9', a technique which needs little training and
nothing too fancy or expensive in the way of laboratory equipment, and is
rapidly eclipsing all other GM methods.
RNAi - lite GM bug busters
December 2015
By 2020, Monsanto plans to have the first two 'RNAi' insecticidal products on the market: one is an 'RNAi' spray to kill potato beetles, the other is an 'RNAi'-enhanced corn to kill corn rootworm.
RNA is produced by DNA and has chemical similarities. It's role is to regulate all aspects of gene function and protein formation. The 'i' in RNAi stands for 'interference, because the synthetic RNA molecules being developed by Monsanto are designed to prevent the creation of proteins. In pests, Monsanto's RNAi kills by interfering with the activity of one of the target pest's vital genes. RNAi is also referred to as 'dsRNA' where 'ds' means 'double-stranded' and is a biotech trick used to confer stability on the normally short-lived, single-stranded RNA. All such RNA is collectively referred to as regulatory RNA.
Monsanto's RNAi spray will be formulated to enable the pesticide to penetrate into the plant tissue, while RNAi-enhanced GM maize will produce its own RNAi pesticide. Either way, the bugs will eat the plant plus the toxic RNAi, and get killed.
By 2020, Monsanto plans to have the first two 'RNAi' insecticidal products on the market: one is an 'RNAi' spray to kill potato beetles, the other is an 'RNAi'-enhanced corn to kill corn rootworm.
RNA is produced by DNA and has chemical similarities. It's role is to regulate all aspects of gene function and protein formation. The 'i' in RNAi stands for 'interference, because the synthetic RNA molecules being developed by Monsanto are designed to prevent the creation of proteins. In pests, Monsanto's RNAi kills by interfering with the activity of one of the target pest's vital genes. RNAi is also referred to as 'dsRNA' where 'ds' means 'double-stranded' and is a biotech trick used to confer stability on the normally short-lived, single-stranded RNA. All such RNA is collectively referred to as regulatory RNA.
Monsanto's RNAi spray will be formulated to enable the pesticide to penetrate into the plant tissue, while RNAi-enhanced GM maize will produce its own RNAi pesticide. Either way, the bugs will eat the plant plus the toxic RNAi, and get killed.
RNAi - Lite GM superweed control?
December 2015
In 2013, Monsanto succeeded in taking out a patent for the next trend in biotechnology. This is based on interfering with gene expression rather than trying to put artificial genes into the plant.
The prime focus of the patent is a clever method for undoing all the problems caused Monsanto's herbicide-tolerant GM crops in the first place.
In 2013, Monsanto succeeded in taking out a patent for the next trend in biotechnology. This is based on interfering with gene expression rather than trying to put artificial genes into the plant.
The prime focus of the patent is a clever method for undoing all the problems caused Monsanto's herbicide-tolerant GM crops in the first place.
RNAi in GM food crops - risks supressed
June 2014
In something of a re-run of the orchestrated defamation of Arpad Pusztai in Scotland in 1998, a respected American professor with 30 years experience to her credit has found herself unable to get funding for her latest biotech-unfriendly research, nor get it published.
She also found Monsanto breathing down her neck in a very unpleasant way.
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| Photo from Creative Commons |
She also found Monsanto breathing down her neck in a very unpleasant way.
Genetic damage from 'inert' dsRNA
December 2013
This year, 2013, kicked of with the
publication of another alarming GM feeding study. It involved double-stranded RNA (dsRNA) which
can be generated by artificial DNA to control existing genes rather than
generate novel proteins (see [1]).
Research has already established that dsRNA
is stable and can transfer from food into the consumer. Once inside, the long chains of dsRNA are
cleaved into an assortment of smaller chains ('siRNA') which can interfere with
metabolic processes.
The reason for the latest feeding study
wasn't anything to do with GM foods or crops.
It was to clarify a technical detail in the way laboratory
investigations of insect genes are carried out.
When studying gene function, it's common practice to disable the gene
using an appropriate siRNA. As a
comparative control in such experiments, scientists have been using a sequence
of dsRNA which couldn't arise naturally.
Their assumption has been that the foreign siRNA won't find any DNA in
the insect genome to interfere with.
However, unexpected observations of changes in gene expression,
pigmentation and developmental timing in control bees (who should have been entirely
'normal') put this assumption in doubt.
Further investigation was clearly warranted.
dsRNA in the field is bad news
August 2013
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| Test tubes in a biotechnology lab. CC photo by wistechcolleges on Flickr |
The latest thing in GM technology uses
a new tactic: it doesn't involve inserting genes, but creates
'RNA-interference' to alter the expression of existing genes. Crops
using one form of this technology, insecticidal double-stranded RNA
(dsRNA), are already in the pipeline.
Just when the official
damage-limitation response to New Zealand scientist Jack Heinemann's warnings about the
risks of dsRNA was fully underway in Australia and New Zealand [1, 2,
3], an even more detailed critic emerged unexpectedly from the
'father' of GM, America.
dsRNA Media Centre
August 2013
 |
| Plant propagation in a lab. CC photo by IRRI Images on Flickr |
It comes as no surprise that safety
assessment of the latest DNA-altered crops with 'ds-RNA' traits, is
being side-stepped. These GM crops have identifiable risks, and
raise many questions which are being 'answered' using assumptions and
generalisations, but scant science (see RNA-MODIFIED FOOD and dsRNA:SILENCING REGULATION - July 2013).
Nor does it come as a surprise that the scientists who published
safety evaluations critical of dsRNA and the dsRNA-based GM wheat now
under development in Australia have come under attack. Needless to
say, the studies they prepared are fully referenced, up-to-date in
their science, and have passed the most rigorous peer-review process
in existence.
Frankenapples
July 2013
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| Non-GM apples. Photo by Scott Bauer, USDA [Public domain] via Wikimedia Commons |
If you've recovered your wits after reading about the latest biotech 'healthy' GM wheat courtesy of its artificial
double-stranded RNA seasoning (see FRANKENWHEAT and RNA-MODIFIED FOOD - July 2013), spare a thought for the humble
apple.
Non-organic apples already have a
stunning array of pesticides in and on them. Forty-two have shown up
in US Department of Agriculture tests. These chemicals include
endocrine disruptors and suspected neurotoxins linked to ADHD.
A major reason for the application of
all these pesticides is the exceptionally narrow gene-base of the
modern apple. We rely on a very
few choice varieties cloned from a single parent by repeated
grafting. Our apples have lost their ability to get along on their
own.
As if things
weren't bad enough, the latest craze is non-browning GM apples which
have artificial dsRNA to add to the mix. This biotech bit blocks the
production of the enzyme which causes a damaged apple to turn brown.
It's
been pointed out that the browning of an apple's cut surface is an
important defense mechanism against the entry of pathogens. The
non-browning varieties may therefore need even more
chemicals to keep them
disease-free.
OUR COMMENT
There's a good case here for for buying old-fashioned apples which have been grown locally, and are organic if at all possible.
SOURCE:
- Katherine Paul and Ronnie Cummins, Frankenapple: Bad News No Matter How You Slice It, Organic Consumers Association, 17.04.13
Frankenwheat
July 2013
 |
| Wheat. CC photo by Wheat Initiative on Flickr |
The latest development in genetic modification isn't inserting
genes, it's inserting DNA to
induce RNA interference, in particular double-stranded RNA, 'dsRNA' .
As
described in RNA-MODIFIED FOOD - July 2013, the
technique has a huge potential for side-effects. Reading this, “How
can anyone still think it's safe to apply (RNA interference) in
genetic modification?” (Institute of Science in Society).
Yet, dsRNA
technology is in several pipe-line GM crops, one of which is a major
global staple food, wheat.
This GM wheat is
being developed in Australia* to have altered starch composition.
The intention seems to be to create wheat grain with starch which is less
digestible than normal. The hope is this will make it 'healthier' by improving
large bowel health and cholesterol levels, and by reducing blood
sugar in the same way as oats, rye, lentils and peas do.
A database
investigation, however, has revealed a number of side-effects which
will not be so healthy.
dsRNA: silencing regulation
July 2013
 |
| Photo from Creative Commons by CIMMYT on Flickr |
If
you've just read RNA-MODIFIED FOOD - July
2013, you'll be aware that this latest GM development carries some
serious new risks.
This
latest GM fad doesn't introduce novel genes or proteins but creates
much trickier transgenic regulatory RNA elements.
Now, you
may be wondering whether our regulators are awake to the problems?
Lip-service is frequently paid to the 'precautionary principle', but rarely backed up by action. The prevailing regulatory culture seems to be one in which marketing of novel materials is encouraged to proceed until some proof of harm emerges. Scientific uncertainty is not used as a reason to delay their launch.
RNA-modified food
July 2013
 |
| Image of biotechnology from Creative Commons / United Soybean Board on Flickr |
Up until now, all major commercial GM
crops have been created by inserting artificial genes.
'Genes' are stretches of DNA (see definitions below)
which the cell uses to create specific proteins.
So far, the novel
proteins in GM crops have fallen into only two categories: they have
either been enzymes which confer tolerance to a weed-killer (such as
'Roundup'), or have been analogues (adapted look-alikes) of bacterial proteins (such as
'Bt') which kill crop pests.
'New' GM crops now
entering the market are simply an extension of these older ones: they
have been 'stacked' with combinations of the same genes. Typical
biotech crops available to farmers have tolerance to more than one
herbicide, and produce several different insecticides.
COMMENT This sort of GM tactic will, ultimately, be self-limiting. Accelerated weed-tolerance to the favoured herbicides, accelerated insect-resistance to the novel insecticides, and constitutional constraints on how much foreign protein a plant can be made to churn out while remaining healthy will make it unsustainable.
However, genes,
Roundup-resistance and Bt insecticides are old-hat. Biotech science
has moved on.
Genetic engineers
have turned their attention away from creating genes and novel
proteins, to the much more vast field of non-gene DNA.
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