Genetic engineering is the procedure of physically adding new DNA to a life form. The objective is to include at least one new characteristics that are not officially found in that living being. Cases of hereditarily designed (transgenic) life forms right now available incorporate plants with imperviousness to a few creepy crawlies, plants that can endure herbicides, and products with adjusted oil content.
Genetic engineering is a technique of biotechnology which deals with studies on the restructuring of the genotypes. The genotype is not simply a mechanical sum of genes, but a complex, formed during the evolution of organisms system. Genetic engineering allows any of the operations in the test tube to transfer genetic information from one organism to another. Gene transfer provides an opportunity to overcome interspecific barriers, and send individual hereditary characteristics of certain organisms to others.
The theme of genetic engineering in recent times has become increasingly popular. Most attention is paid to negative consequences, which can lead to the development of this branch of science, and in a very small way highlights the benefits that could be derived from genetic engineering.
Genetic engineering - the science of the future. At the moment, around the world millions of hectares of land planted with transgenic plants are created by a unique medication, the new producers of useful substances. Eventually genetic engineering will lead to further advances in medicine, agriculture, food industry and in animal husbandry.
History of genetic engineering
The history of high biomedical technologies, genetic research methods, as, indeed, most genetic engineering is directly connected with the eternal human desire to improve the breeds of domestic animals and cultivated by people of cultivated plants. Taking, certain species of groups of animals and plants and crossing them with each other, people not having correct idea about the inner essence of the processes occurring within living beings, however, many hundreds and thousands of years creating improved breeds of animals and varieties of plants that had certain useful and necessary for people properties.
In XVIII and XIX centuries many attempts have been made to figure out how to transmit characteristics from generation to generation. One important discovery was made in 1760 by botanist, Koelreuter, which crossed two species of tobacco, leaving the stamens with the pollen of one species on the pistils of another. Plants derived from hybrid seeds had characteristics intermediate between the characteristics of both parents. Koelreuter, made this logical conclusion that parental characteristics are transmitted through the pollen (sperm) and ovules (egg cells). However, neither he nor his contemporaries involved in the hybridization of plants and animals, failed to disclose the nature of transmission mechanism of heredity. This is partly due to the fact that in those days were not yet known cytological basis of this mechanism, but mainly to the fact that scientists have tried to study the inheritance of all characteristics of plants at the same time.
In 1900, after it became known the details of cell division type mitosis, meiosis and fertilization, three of the researcher - de Vries in Holland, Correns in Germany, and chermak in Austria conducted a series of experiments and independently from each other a second time discovered the laws of heredity, Mendel described earlier. Later, found an article by Mendel, in which these laws have been articulated for 35 years before them, these scientists unanimously paid tribute to the scientist-monk, describing the two fundamental laws of heredity in his name.
In the first decade of the twentieth century, experiments were conducted with a variety of plants and animals and made numerous observations concerning the inheritance of traits in humans that have clearly shown that all these organisms heredity is subject to the same fundamental laws. It was found that Mendel described the factors that determine individual feature, located in the chromosomes of the cell nucleus. Subsequently, in 1909, these units were named by the Danish botanist Johannsen genes (from the Greek word "GE-nose" - the kind, origin), American scientist William Sutton noticed an amazing similarity between the behavior of chromosomes during the formation of gametes (sex cells), fertilization and Mendelian transmission of hereditary factors - genes. On the basis of these brilliant discoveries and created a so-called chromosome theory of heredity.
Applications of genetic engineering
Being committed scientific discoveries in human genetics have actually a revolutionary meaning, since we are talking about the possibility of creating a "map of the human genome," or "pathological anatomy of the human genome". This genetic map will allow you to install on the long helix of DNA, location of genes responsible for certain hereditary diseases. As suggested by geneticists, these unlimited possibilities formed the basis for ideas application in clinical practice, the so-called gene therapy, which represents the direction of treatment of patients, which is associated with the replacement of the affected genes with high medical-biological technologies and genetic engineering. The invasion of part of the genetic systems and providing their vital activity is possible both on the level of physical (any physical, having certain structural and functional differences) of the cells of the body, and at the level of sexual reproducing (germ) and germ (embryonic) cells.
Genetic engineering as a kind of therapy to treat a genetic disease - is associated with the supply of the respective non-defective DNA molecules with the aim of replacing her with that gene - segment of a chromosome which contains a defect, or for incorporation into the genetic material of a person by merging with the so-called somatic cells of the human body with a genetic defect. The task of genetic engineering in humans is the provision of targeting a gene to fix, in the direction of the correct functioning and security of a person suffering from a genetic disease, the normal, unmodified version of the gene. Unlike medication, drug therapy, such treatment is called genetic engineering, will be able, apparently, to give the patient a long, prolonged, highly effective, bringing great relief and benefits of treatment.
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Scientific evidence of the dangers of genetic engineering
It should be noted that along with progress that carries the development of genetic engineering, and isolated and some of the facts of the dangers of genetic engineering, the main of which are presented below.
1. Genetic engineering is fundamentally different from developing new varieties and breeds. Artificial addition of foreign genes strongly violates the precisely regulated genetic control of normal cells. Manipulation of genes is fundamentally different from a combination of maternal and paternal chromosomes, which occurs with natural mating.
2. Currently, genetic engineering is technically flawed, since she is unable to manage the process of embedding a new gene. Therefore, it is impossible to foresee the place of installation and the added effects of the gene. Even if the location of the gene it would be possible to set after its incorporation into the genome, the available information about DNA is very incomplete in order to predict the results.
3. Artificially adding a foreign gene emergency may generate hazardous substances. In the worst case, it can be toxic substances, allergens or other harmful substances. Information about such opportunities is still very incomplete.
4. There is no completely reliable methods of testing for harmlessness. More than 10% of serious side effects of new drugs not possible to identify, in spite of carefully conducted studies on the safety. The degree of risk that the hazardous properties of new, modified using genetic engineering of food, unnoticed, likely, much more than in the case of drugs.
5. The currently existing requirements for the test for harmlessness is extremely insufficient. They are clearly designed to simplify the approval procedure. They allow you to use very insensitive test methods for harmlessness. Therefore there is a significant risk that hazardous foods will be able to pass the test undetected.
6. Established to date with genetically engineered foods do not have any significant value for mankind. These products satisfy mainly just commercial interests.
7. Knowledge about the effects on the environment modified using genetic engineering organisms, introduced there, is completely inadequate. Not proven yet that modified genetically engineered organisms will not have a harmful impact on the environment. Environmentalists suggested various potential environmental complications. For example, there are many opportunities for uncontrolled proliferation, potentially dangerous genes used in genetic engineering, including gene transfer by bacteria and viruses. The complications caused in the environment probably cannot be corrected, as released genes cannot be recalled.
8. There may be a new and dangerous viruses. It is experimentally shown that the genes embedded in the genome of a virus can connect to the genes of infectious viruses (so called recombination). These new viruses can be more aggressive than the original. Viruses can become less species-specific. For example, plant viruses can be harmful to beneficial insects, animals, and humans.
9. Knowledge about the hereditary substance, DNA, is very incomplete. Known about the function of only three percent of DNA. It is risky to manipulate complex systems, knowledge of which is incomplete. Extensive experience in the field of biology, ecology and medicine shows that it can cause serious unpredictable problems and disorders.
10. Genetic engineering will not help to solve the problem of hunger in the world. The assertion that genetic engineering can make a significant contribution to the solution of the problem of hunger in the world, is scientifically unfounded myth.
The possibilities of genetic engineering
An important part of biotechnology is genetic engineering. Born in the early 70-ies, it has made today a great success. Genetic engineering techniques transform cells of bacteria, yeast and mammals of the "factories" for large-scale production of any protein. This gives you the opportunity to analyze in detail the structure and functions of proteins and their use as medicines. Currently, Escherichia coli (E. coli) became the supplier of such important hormones as insulin and somatotropin. Previously, insulin was obtained from cells of the pancreas of animals, so the cost was very high. To obtain 100 g of crystalline insulin requires 800-1000 kg of the pancreas, and one iron cow weighs 200 - 250 grams. It makes the insulin is expensive and inaccessible to a wide range of diabetics. In 1978, researchers from the company "Genentech" first received insulin in a specially constructed strain of Escherichia coli. Insulin consists of two polypeptide chains A and b of length 20 and 30 amino acids. When connecting them formed disulfide bonds of native double-stranded insulin. It has been shown that it does not contain any E. coli proteins, endotoxins and other impurities, has no side effects as insulin animals, and the biological activity of it is no different. Subsequently, the E. coli cells was carried out the synthesis of proinsulin, which in the matrix RNA using reverse transcriptase synthesized its DNA copy. Obtained after purification of proinsulin and its split the received native insulin, the stages of extraction and isolation of the hormone was reduced to a minimum. From 1000 liters of culture liquid can be up to 200 grams of hormone, which is equivalent to the amount of insulin secreted from 1600 kg pancreas of pigs or cows.
Now, it is difficult to predict all the features that will be implemented in the next few decades.