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.

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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