organisms change climate.
|Widespread distribution of genetically modified
organisms (GMO), which affects the Environment negatively, is a great
ecological experiment with an unknown end. Transgenization (via pollen,
seeds and organic rests) leads to the genetical pollution of
Environment, to the decrease of biovariety. Disappearance of bacteria,
plants and animals, which play an important role in the ecological
balance, could be reason of climate change. The scientists repeatedly
warned about hazard of GMO for the Environment (Ho Mae-Wan and Tappeser
Beatrix, 1997; Pusztai, 2001; Chirkov, 2002; Kuznetcov et al., 2004;
World Scientists Statement and others).
The term "Genetically Modified Organisms" refers to plants and animals with genes transferred from other species in order to produce certain characteristics, such as resistance to pests and herbicides. GMO with modified genetical material are not found in nature under natural conditions. There are several reasons for the GMO hazard to the Environment.
Firstly, the replacement of natural plants by GMO steady to insects and herbicides, leads to a decrease of plant variety. The second reason is connected with the destruction of nutritional ways and therefore disappearance of different animal species. The third, more dangerous reason is mediated by possibility of foreign genes to be introduced into the genome of cells of other organisms as a result of horizontal gene transfer (from species to species). This could lead to mutations and infertility.
In-fourth, serious influence on the Environment was performed by changing the genome of ice nucleation-active bacteria (Pseudomonas syringae and Erwinia herbicola) for protection plant crops from frost damage (Lindow et al., 1978; Orser et al., 1985; Kozloff et al., 1991; Turner et al., 1991; Wilson and Lindow, 1994; Chirkov, 2002). These bacteria play an important role in formation atmospheric ice nuclei and raindrops.
Negative effect of GMO on animals was shown in many investigations. Larvae of the monarch butterfly, Danaus plexippus, reared on milkweed leaves dusted with pollen from Bt corn, ate less, grew more slowly and suffered higher mortality than larvae reared on leaves dusted with untransformed corn pollen or on leaves without pollen (Losey, 1999). The results of Zangerl et al. (2001) indicated that Bt corn incorporating event 176 could have adverse sublethal effects on black swallowtails in the field. Reinforcement of anxiety in rats and high mortality of newborn rats in first generation after addition of GM-soy (Roundup Ready, RR) into the food of rat females (before pregnancy, during pregnancy and during lactation) were revealed in our experiments (Ermakova, 2005, preliminary studies).
There are two standart methods usually used to introduce a new DNA (gene) into the cell of a plant which is going to be modified: the “shot-gun” technique and “shot-gun” tumefaciens method. Both methods are not perfect and don’t guarantee safety of the GM-organisms created with their help for the Environment.
“The “shot-gun” technique, also called biolistic transformation, was developed by Sanford in 1987. It can be used to transform all kind of plants, bacteria, moulds, algae and animals. A device was built to shoot small particles of gold or tungsten against cells. These particles can be coated with DNA material and are so small that they can penetrate cells without lasting damage. This method is less dangerous than the Agrobacterium method.
Agrobacter tumefaciens is a bacterium which was found in soil. This bacterium infects the plant and transfers its DNA to the plant with the help of plasmids (DNA). Some strains attack plants transferring a small part or its genetic material to the plant causing tumors. In the tissue of the tumors Agrobacterium tumefaciens can live and produces there new nutrients (opines). The plasmids are responsible for the tumor activity and are therefore called ``Tumor inducing Plasmids'' (Ti-plasmids). The T-DNA is the part of the Ti-plasmids which is transfered to the plant (Transfer-DNA).
Special techniques made possible to modify the Ti-plasmids and the T-DNA to avoid the production of phytohormones responsible for the tumor activity, the opine synthesis gene were cut out and gene of the resistance to antibiotic Neomycin and Kanamycin was introduced. Agrobacterium method is not good for Cereals and for the regeneration of plants whose cell walls were enzymic digested.
The supporters of GMO assert that the GM-components are completely destroyed in the digestive tract of men and animals. However rings of plasmids are steadier than it was believed against the digestion.
Plasmid DNA and GM-DNA were found in micro flora of intestine and in saliva in man (Mercer et al., 1998; Coghlan, 2002). Experimental researches in mice showed that ingested foreign DNA can persist in fragmented form in the gastrointestinal tract, penetrate the intestinal wall, and reach the nuclei of leukocytes, spleen and liver cells (Schubbert et al., 1994). Important data were obtained when a plasmid containing the gene for the green fluorescent protein (pEGFP-C1) was fed to pregnant mice. Foreign DNA, orally ingested by pregnant mice, was discovered in blood (leukocytes), spleen, liver, heart, brain, testes and other organs of foetuses and newborn animals. The foreign DNA was detected in association with both chromatids (Schubbert et al., 1998). So, maternally ingested foreign DNA could be potential mutagens for the developing fetus.
Transgenic organisms as the fire grasp increasing areas on the Earth. The majority of transgenic organisms become fruitless after one or more generations. Global transgenization can result in disappearance of significant part of alive organisms on the planet, in climate change, in destruction of biosphere. It is necessary to stop the global transgenization of the planet and to start the recovery of the disturbed Environment urgently.
Irina Ermakova – doctor of biology,