Genetic engineering is the manipulation of genetic material by either molecular biological techniques or by selective breeding. While selective breeding has been practiced for thousands of years (domestication of the dog; farming corn; brewer's yeast) the manipulation of genetic material in vitro was developed in the 1970s. The DNA is manipulated within a test tube and subsequently introduced back into a cell in order to change the processes of a cell or organism. In its simplest conception a molecular biologist can combine molecules of DNA from different organisms encoding different properties. Genetic engineering, also called
Types Of Genetic Engineering:
1. Analytical Genetic Engineering:
This is the research branch of genetic engineering in which virtual genetic models are created using computer software. Various computer programs are used to theoretically study the implications of various genetic engineering activities if they are to be carried out in practice. For instance, before going ahead and splicing two different genes in actual practice, preparing an analytical model based upon an appropriate program, developed for the purpose, will give the researchers an idea whether such splicing would be successful at all and if successful, if the desired end would be achieved. This is a better way of carrying out the trial-and-error stage and reduces risks of disaster during experiments using real organisms, especially animals.
2. Applied Genetic Engineering:
Applied genetic engineering, as the name suggests, is that field of genetic engineering which pertains to practical application of genetic engineering tools to manipulate the genes of living organisms for making genetic copies of them or to introduce certain different characteristics in them that are not usual for the subjects. The first instance is what we typically refer to as cloning and the second instance refers to the premises of transgenesis. While cloning is a highly regulated and controversial field, it has been carried out in various subjects of animal and plant species with mixed results and uncertain success rates. Transgenesis, on the other hand, is a comparatively common area and most of us have partaken of the results of transgenesis sometime or the other. Don't believe me? Well, what about hybrid fruits and vegetables? They are the most common and abundant examples of transgenesis.
3. Chemical Genetic Engineering:
Chemical genetic engineering can be called the grass root level of applied genetic engineering as it deals with separating, classifying and graphing genes to prepare them for applied genetic engineering activities and experiments. Chemical genetic engineering includes genetic mapping, studying genetic interaction and genetic coding. In genetic mapping, DNA fragments are assigned to individual chromosomes and thus, a genetic map is created after the complete DNA sequencing of a subject is done. Genetic mapping is very crucial to understanding the disease-gene link and this understanding lays the foundation of various gene therapies. Studying genetic interactions helps researchers understand exactly what set and combination of genes would produce a particular phenotype or set of morphological, physiological and behavioral characteristics. Genetic coding deals with studying and experimenting with amino acid sequences of DNA and RNA so as to understand the heredity trends and characteristics of a subject. This helps in understanding the bases, possibilities and conditions of undesirable hereditary characteristics, defects and disease in a bid to come out with medical solutions for the same.
Applications of Genetic Engineering:
An important application of recombinant DNA technology is to alter the genotype of crop plants to make them more productive, nutritious, rich in proteins, disease resistant, and less fertilizer consuming. Recombinant DNA technology and tissue culture techniques can produce high yielding cereals, pulses and vegetable crops. Some plants have been genetically programmed to yield high protein grains that could show resistance to heat, moisture and diseases. Some plants may even develop their own fertilizers some have been genetically transformed to make their own insecticides. Through genetic engineering some varieties have been produced that could directly fix atmospheric nitrogen and thus there is no dependence on fertilizers. Scientists have developed transgenic potato, tobacco, cotton, corn, strawberry, rape seeds that are resistant to insect pests and certain weedicides.
Genetic engineering has been gaining importance over the last few years and it will become more important in the current century as genetic diseases become more prevalent and agricultural area is reduced. Genetic engineering plays significant role in the production of medicines. Microorganisms and plant based substances are now being manipulated to produce large amount of useful drugs, vaccines, enzymes and hormones at low costs. Genetic engineering is concerned with the study (inheritance pattern of diseases in man and collection of human genes that could provide a complete map for inheritance of healthy individuals. Gene therapy by which healthy genes can be inserted directly into a person with malfunctioning genes is perhaps the most revolutionary and most promising aspect of genetic engineering. The use of gene therapy has been approved in more than 400 clinical trials for diseases such as cystic fibres emphysema, muscular dystrophy, adenosine deaminase deficiency.
Recombinant DNA technology has tremendous scope in energy production. Through this technology Ii is now possible to bioengineer energy crops or biofuels that grow rapidly to yield huge biomass that used as fuel or can be processed into oils, alcohols, diesel, or other energy products. The waste from these can be converted into methane. Genetic engineers are trying to transfer gene for cellulase to proper organisms which can be used to convert wastes like sawdust and cornstalks first to sugar and then to alcohol.
Genetically designed bacteria are put into use for generating industrial chemicals. A variety of organic chemicals can be synthesised at large scale with the help of genetically engineered microorganisms. Glucose can be synthesised from sucrose with the help of enzymes obtained from genetically modified organisms. Now-a-days with the help of genetic engineering strains of bacteria and cyanobacteria have been developed which can synthesize ammonia at large scale that can be used in manufacture of fertilisers at much cheaper costs. Microbes are being developed which will help in conversion of Cellulose to sugar and from sugar to ethanol. Recombinant DNA technology can also be used to monitor the degradation of garbage, petroleum products, naphthalene and other industrial wastes.
1. Contributes significantly to biotechnology research.
1. Has associated consequences and possible irreversible effects.