Biology Reference
In-Depth Information
Table 14.7: Some Risk Issues Relevant to Releases of Genetically Modified Insects into the
Environment.
A. Attributes of the unmodified organism
l
What is the origin of the genetically modified organism (indigenous or nonindigenous) in the
accessible environment?
l
What is the insect's trophic level (predator, parasite, plant feeder) and host range?
l
What other ecological relationships does it have?
l
How easy is it to monitor and control it?
l
How does it survive during periods of environmental stress?
l
What is the potential for gene exchange with other populations?
l
Is the insect involved in basic ecosystem processes?
B. Attributes of the genetic alteration
l
What is the intent of the genetic alteration?
l
What is the nature and function of the genetic alteration?
l
How well characterized is the genetic modification?
l
How stable is the genetic alteration?
C. Phenotype of modified organism compared to unmodified organism
l
What is the host/prey range?
l
How fit and effective is the genetically modified strain?
l
What is the expression level of the trait?
l
Has the alteration changed the organism's susceptibility to control by natural or artificial means?
l
What are the environmental limits to growth or reproduction (habitat, microhabitat)?
l
How similar is the genetically modified strain being tested to populations previously evaluated in field
tests?
D. Attributes of the accessible environment
l
Describe the accessible environment, whether there are alternate hosts or prey, wild relatives within
dispersal capability of the organisms, and the relationship of the site to the potential geographic range
of the new strain.
l
Are there endangered/threatened species present that could be affected?
l
Are there agents that could move the new strain present in the release environment?
l
Do the test conditions provide a realistic simulation to nature?
l
How effective are the monitoring and mitigation plans?
(Modified from Tiedje et al. 1989; USDA 1991; and from a discussion held at a conference on “Risks of Releasing Transgenic
Arthropod Natural Enemies,” held November 13-16, 1993 in Gainesville, Florida.)
incompatibility on
Culex pipiens
populations and suggested that it could be
used as a means of controlling them (
Prout 1994, Sinkins and O'Neill 2000
).
Yen and Barr (1974)
found the cause of the incompatibility in
Cx. pipiens
was due to the presence of
Wolbachia
. Experiments were conducted, but
the incompatibility produced was incomplete because transmission was not
fully efficient (
Pal 1974
). However, there is hope that genetic control by this
approach could become effective.
Turelli and Hoffmann (1991)
reported
that
Wolbachia
spread rapidly in field populations of
Drosophila simulans
in California in a “natural” experiment.
Turelli et al. (1992)
concluded that
cytoplasmic incompatibility induced by
Wolbachia
, “therefore provides a
