The scientific technique used to detect the possible risks of GEOs is called risk modeling. It includes both laboratory and field techniques.
The identification of possible risks of GEOs is the first step of risk modeling. We cannot know the risk suitable experiments are carried out under the laboratory conditions. It is supposed that risks of GEOs may arise due to-
• The incorporation of gene for hazardous trait into an organism.
• The escaping of GEOs into the environment.
• The survival of the harmful organism in the environment.
• The multiplication of the organism in that environment.
• The exchange of genes among the organisms in the environment.
• The actual harmfulness of the GEO.
The genes for hazardous traits can be detected by using the techniques of molecular biology. Microbiological techniques are followed to know the environmental conditions suitable for the survival and multiplication of the organism. Co-cultivation of GEOs with other microbes in microcoesum is used to detect the possibility of exchanging their genetic material. The harmfulness of the GEOs can be detected and estimated by adopting clinical and pharmaceutical methods. Biochemical methods are of much use for this purpose.
In the case of transgenic plants the soil type required, temperature range, pH range, manorial requirements, pathogenecity, sensitivity to herbicides, season, climate required, etc. are all tested in green houses. For transgenic animals, such experiments are conducted in small restricted areas in the laboratory.
If the GEO gives satisfactory results, it is then subjected to field tests. For this purpose , scientists set up a national level conference with environmentalists, medical professionals and public. The laboratory results were discussed with them. The conference recommends the national committee to allow the scientists to do field tests.
Field tests are conducted in isolated areas with full participation of public, environmentalists and doctors. If the field tests are satisfactory, the GEO may be sent for patents.
The assessment of risks of GEOs by using scientific data obtained from risk modeling is called risk assessment or risk evaluation. It helps us to choose harmless GEOs for deliberate release in the environment.
The GEOs will be much consideration, if they have the following qualities:
Attributes of Genetic Alteration:
• Poor previous characterization.
• Low genetic stability.
• Desired genes in multiple copies.
• Desired genes coding for new proteins.
• Target gene taken from unrelated species.
• Engineered through self- transmissible vectors.
• Unrelated source of vector to the GEO.
• Functional vector DNA in GEO.
• Easy monitoring of spreading of GEO
Attributes of Parent Organism:
• High self- propagating efficiency.
• No control agent known for it in the nature.
• Exotic origin.
• Symbiotic or pathogenic habit.
• A few pets to the organism.
• Long tern survival.
• Broad geographic range of distribution.
• Frequent gene exchange among the wild organisms.
• High turnover rate.
• High mobility.
Phenotypic Attributes of GEO in comparison with the Parent Organism:
• Increased fitness to the environment.
• Increase rate of infectivity.
• Shifted host-range.
• Expanded range of substrates.
• Shifted environmental limits.
• Increased disease resistance.
• Decreased susceptibility to control.
• Expression of trait depending on some factors.
• No previous release in the nature.
Attributes of the Environment:
• Liability to certain selection pressures.
• Presence of wild relatives of GEO in the nature.
• Presence of dispersal agents.
• Having certain key roles in the nature.
• Presence of alternative symbionts.
• Broad environmental range.
• Uncontrolled public access to the site.
• Less monitoring tests.
• Endangered species already present in the nature.
• No geographical isolation.
• Important crops exist in the area while doing field trial.
If a GEO has all the above said qualities and is harmless to man, animals and plants, it is considered to be a suitable one to release.
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