GMO Myths and Truths

1.4 Myth: Cisgenics/intragenics is a safe form of GM because no
foreign genes are involved
Truth: Cisgenic/intragenic foods are just as risky as any other
GM food
Some scientists and GM proponents are
promoting a branch of genetic engineering they
have termed “cisgenics” or “intragenics”, which
they say only uses genes from the species to be
engineered, or a related species. They say that
cisgenic/intragenic GMOs are safer and more
publicly acceptable than transgenic GMOs, on
the claimed grounds that no foreign genes are
introduced. 27,28
An article on the pro-GM Biofortified website,
“Cisgenics – transgenics without the transgene”,
bluntly states the public relations value of
cisgenics: “The central theme is to placate the
misinformed public opinion by using clever
technologies to circumvent traditional unfounded
criticisms of biotechnology.” 29
An example of a cisgenic product is the
GM “Arctic” non-browning apple, which a
Canadian biotechnology company has applied to
commercialise in the US and Canada. 30,31
GM proponents appear to see intragenics/
cisgenics as a way of pushing GM foods through
regulatory barriers. As two researchers write: “A
strong case has been made for cisgenic plants to
come under a new regulatory tier with reduced
regulatory oversight or to be exempted from GM
regulation.” 31
However, in reality, cisgenics and intragenics
are just transgenics by another name. The artificial
nature of the transgene construct and its way of
introduction into the host plant genome make
cisgenics/intragenics just as transgenic as crossspecies
transfers.
The word “intragenic” implies that only genes
within the genome of a single species are being
manipulated. But although it is possible to isolate
a gene from maize, for example, and then put it
back into maize, this will not be a purely intragenic
process. This is because in order to put the gene
back into maize, it is necessary to link it to other
sequences at least from bacteria and possibly also
from viruses, other organisms, and even synthetic
DNA. Inevitably, “intragenic” gene transfer uses
sequences from other organisms. Thus, though
the gene of interest may be from the same species
as the recipient organism, the totality of the
genetically modified DNA introduced is not purely
intragenic, but is transgenic, in the sense that
some of the genetic elements that are introduced
into the recipient plant are derived from another
species.
The supposedly intragenic Arctic apple is
clearly transgenic, in that sequences from foreign
species were part of the DNA construct that was
introduced into the apple. This introduces major
uncertainties into the plant’s functioning, because
the effects that those foreign sequences might
have on the recipient organism are unknown.
The process of inserting any fragment of
DNA, whether intragenic or transgenic, into an
organism via the GM transformation process
carries the same risks. These risks have been
discussed in detail, above. Insertion takes place
in an uncontrolled manner and results in at least
one insertional mutation event within the DNA of
the recipient organism. The insertional event will
interrupt some sequence within the DNA of the
organism and interfere with any natural function
that the interrupted DNA may carry. For instance,
if the insertion occurs in the middle of a gene, the
gene’s function could be destroyed. As a result,
the organism will lose the cellular function that
the gene encodes. In addition, mutagenic effects
on the plant’s DNA caused by the tissue culture
process occur with cisgenics/intragenics, just as
with transgenics.
In conclusion, cisgenic/intragenic plants carry
the same environmental and health risks as
transgenic GM plants.
GMO Myths and Truths 20