Hope Not Hype - Third World Network

134 Hope Not Hype
[Generation-to-generation transfer:] [T]he RNAi effect is remarkably long lived. Potent
interference is routinely observed not only in the injected animal but also in all of the injected
animal’s progeny. Thus, interference can be inherited…For many genes, interference can
persist for at least one full generation after the one receiving the injection, and for certain
genes, interference can be observed to transmit in the germ line apparently indefinitely
(Tabara et al., 1998).
However, ERMA explicitly rejected RNA of this type as genetic material:
siRNA, antisense RNA, shRNA, micro-RNAs and dsRNA molecules that have been produced
and purified are not genetic material (ERMA, 2006, p. 58).
The HSNO Act is silent on what constitutes genetic material, but ERMA equates
genetic material with “genetic element” (ERMA, 2006). Genetic element is defined by
the Act as “any genes, nucleic acids, or other molecules from the organism that can,
without human intervention, replicate in a biological system and transfer a character or
trait to another organism or to subsequent generations of the organism” (Part 1 s2). By
virtue of RNA being able to form replication pathways without human intervention, it is
genetic material and/or a genetic element. Therefore, it can be directly deduced that
organisms exposed to in vitro RNA or that have any ancestral history deriving from RNA
manipulated in vitro or synthesized from DNA that has any ancestral history of in vitro
manipulation, have been genetically modified.
It appears that ERMA is correct in thinking that genetic elements are at least a subset,
if not the full set, of all that can be considered genetic material. However, because dsRNA
is clearly a genetic element as per the definition of the Act, it is not clear how ERMA
excluded it as a molecule that creates GMOs.
Replication of dsRNA and inheritance of gene silencing by various biochemical pathways
The ability to replicate dsRNA molecules is nearly ubiquitous.
Pioneering observations on PTGS/RNAi were reported in plants, but later on RNAi-related
events were described in almost all eukaryotic organisms, including protozoa, flies,
nematodes, insects, parasites, and mouse and human cell lines (Agrawal et al., 2003, p.
657).
This is also the case for bacteria (Gottesman, 2005; Tchurikov et al., 2000). Thus, in
theory, many organisms exposed to dsRNA will be capable of replicating and “expressing”
a gene silencing trait, just as they would be able to replicate DNA and potentially express
DNA-mediated traits, depending on certain conditions being met. For example, expression
of a gene composed of DNA requires compatibility between various important DNA
sequences and proteins that serve as transcription factors. Similarly, gene silencing will
require compatibility between existing genes and the small dsRNA molecule that first
enters the cell (Buratowksi and Moazed, 2005).