Hope Not Hype - Third World Network

130 Hope Not Hype
In New Zealand, the Environmental Risk Management Authority (ERMA) regulates
activities involving genetic modification under the Hazardous Substances and New
Organisms (HSNO) Act. In 2005, ERMA adopted a policy that identified certain forms of
RNA that cause gene silencing, e.g., RNAi, antisense, dsRNA-mediated methylation and
so on, as lying outside the scope of its governing legislation (ERMA, 2006).
Gene silencing by so-called “regulatory RNAs”, because they modulate gene
expression, is a recently discovered phenomenon that is operative in organisms of all
biological kingdoms. The RNA molecules involved are called, variously, dsRNA, short/
small interfering RNAs (siRNAs), repeat-associated short interfering RNAs (rasiRNAs),
microRNAs (miRNAs) and short-hairpin (sh)RNA (Denli and Hannon, 2003; Meister
and Tuschl, 2004; Paddison et al., 2002). These cause the related phenomena known by
many different names such as RNAi, RNA silencing, inhibitory RNA, quelling, MSUD,
co-suppression and post-transcriptional gene silencing (PTGS) and even paramutation
(Ashe and Whitelaw, 2007; Chandler and Vaucheret, 2001). The precursors of dsRNAmediated-silencing
replication are provided by the reaction transcription and include dsRNA
as a co-factor.
Gene silencing is rapidly being adopted as a GM technology, making more widely
available the tools necessary to construct the recombinant DNA, or transgenes, that produce
dsRNA when inserted into a recipient organism. In vitro synthesized dsRNA also can be
introduced directly without creating recombinant DNA because dsRNA is far more
horizontally mobile (i.e., infectious) than DNA (as discussed below).
Regulatory RNA molecules that are derived from in vitro manipulated DNA, such
that the DNA was made a stable part of an organism’s genome, were deemed to be covered
by the HSNO Act (ERMA, 2006). On the other hand, regulatory RNA molecules derived
through in vitro synthesis or extracted from one organism and then introduced into another,
were considered not to be subject to the HSNO Act. The rationale for the exclusion of the
latter set of approaches resulting in gene silencing is stated as follows:
Treatment of organisms with these molecules affects protein expression in the cell but not
by modifying the organism’s genome. The use of RNAi technology is not therefore considered
to be the development of a genetically modified organism under the HSNO Act as the genes
of the host organism are not modified, although it is acknowledged that the pattern of gene
expression in the host is modified (ERMA, 2006, p. 58).
This interpretation of “genome”, a term not defined by the Act, is unclear, but it has
the effect of excluding the evaluation of the risks arising from certain types of in vitro
modified RNA, or RNA derived from modified DNA and synthesized in a cell-free system;
these same molecules are unambiguously captured under the Biosafety Protocol. It would
also be inconsistent with a common definition of the term “genome” as all material that
could transfer traits to other organisms and to descendants. 1 ERMA’s flawed description
1
“Genome” is a derivative of “genetics”, which is defined by the US Congress Office of Technology
Assessment as “The study of the patterns of inheritance of specific traits” (US Congress Office of
Technology Assessment. http://www.bis.med.jhmi.edu/Dan/DOE/prim6.html. Date of access: 4 January
1999). This definition is inclusive and does not assume the physical basis of traits as DNA.