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.
Three experiments were carried out in which bees were fed a single meal of the dsRNA at a specific point in their early development. Changes in gene expression were then recorded at two different larval stages and in adult working bees.
Far from the assumed absence of response,
the researchers found that overall, some 1400 genes had altered expression,
representing around 10% of currently identified bee genes. The changes included both direct effects on
genes and knock-on effects in the downstream gene networks. Affected genes encompassed those involved in
important developmental and metabolic processes, hormones, immunity,
environmental responses, and stress.
Disruption, however, was almost entirely confined to the two immature
forms tested, with only five alterations in gene expression observed in adult
bees.
The authors comment that the triggering of
immune- and stress-responses suggest that the siRNA is being recognised as a
viral infection. They consider it likely
that the bees become habituated to the effects of the siRNA with time, so that
in adult bees the genomic disruption had faded.
OUR COMMENT
Considering that these bees were fed a single
dose of dsRNA, the disruption caused is huge.
In a 'normal' situation of life-long
consumption of a range of dsRNAs through successive generations, and in a
'normal' situation of environmental stress, effects on the health of the
population would be catastrophic.
Signs that the bees' physiology became
desensitised by the perceived 'viral' attack could make their immune systems
vulnerable to later actual infections.
This particular dsRNA is used only in
laboratory studies, but the potential for equal or greater genomic
disturbances due to other forms of dsRNA
engineered into food crops is of grave concern for wild-life, livestock and
human health.
Scientists are getting away with a lot of
assumptions (a.k.a. bad science) about the action, or lack of action, of
genetic materials which could easily be checked out (a.k.a. good science).
As we've said before:
“Because the transformation needed to
generate dsRNA doesn't involve 'genes' or produce a specific novel protein,
it's likely that the products of this technology will fall through regulatory
loopholes. At the moment, there's no
sign of any regulatory will to close the gaps.
That means it's up to the public to create the will to regulate
before that 'proof of harm' emerges to force the issue the hard way.” [2]
“It's time to demand the development of meaningful
and comprehensive testing protocols: these must be long-term,
multi-generational, include all major tissues and organs, must check for
endocrine effects; they must then be followed up with clinical studies and a
realistic system for monitoring the consuming population.”[1]
“Start complaining to our food regulators
NOW: make sure that dsRNA never gets a chance to cause the havoc it so clearly
can.” [3]
Background:
[1]
RNA MODIFIED FOOD - July 2013
[2]
dsRNA: SILENCING REGULATION - July 2013
[3]
FRANKENWHEAT - July 2013
SOURCE:
· Frances M. F. Numes, et al., 2013, Non-Target Effects of
Green Fluorescent Protein (GFP)-Derived Double-Stranded RNA (dsRNA-GFP) Used in
Honey Bee RNA Interference RNAi Assays, Insects 4,
www.mdpi.com/journal/insects
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