Recombinant DNA techniques have transformed genetic engineering in plants and animal food production, industry and medicine. In most cases, DNA cannot be transferred directly from its original organism (donor) to the recipient organism (host). Instead the donor DNA must be cut and recombined with a matching fragment of DNA from a vector that is, an organism that can carry the donor DNA into the host. The host organism is often a rapidly multiplying microorganism such as a harmless bacterium, which serves as a factory where the recombined DNA can be cloned in large quantities.
The protein produced can then be extracted from the host, purified and used as a genetically engineered product in humans, animals, plants, or bacteria or viruses. The naked DNA can be introduced directly into an organism by techniques such as an injection through the cell walls or plants or into the fertilized egg of an animal.
Recombinant DNA has been used to combat one of the greatest problems in plant food production: the destruction of crops by plant viruses. For example, by transferring the protein coat gene of the zucchini yellow mosaic virus to squash plants that had previously sustained great damage from the virus, scientists were able to create transgenic potato and strawberry plants that are frost-resistant, as well as transgenic tomato plants containing a gene that slows the ripening process of the fruit, which repels spoilage once the tomatoes are off the plant.
Similarly, in animal food production, the growth hormone gene of rainbow trout has been transferred directly into carp eggs. The resultant transgenic carp produce both carp and rainbow trout growth hormones and grow to be one-third larger than normal carp.
As can been seen from the given examples, recombinant DNA in most cases has been beneficial but lack of actual positive results in the majority of cases of study, has shown concern.
Gene transfers also have been applied in the management of industrial wastes. Genetically altered (recombined) bacteria can be used to decompose many forms of garbage and to break down petroleum products. Recombined DNA technology is also used to monitor breakdown of pollutants. Or example Naphthalene, an environmental pollutant present in artificially manufactured soil, can be broken down by the bacterium Pseudomonas fluorescens.
The most affective and the most well know use of recombinant DNA and genetic engineering on the whole has to be in the medical facility. Many people are aware of the hormone insulin being recombined into bacterium cells and used for human needs. Diabetic people now have a rich source of insulin thanks to genetic engineering and recombinant DNA. The media and the public have always supported this idea because it benefits those of us who are less fortunate then us and have diabetes. This practice has been taken that one step further to try to eliminate human disease. scientists are now able to help people in critical conditions with fatal diseases.
However, critics of recombinant DNA fear that the pathogenic, or disease-producing, organisms used in some recombinant DNA experiments might develop extremely infectious forms that could cause worldwide epidemics.
Critics are also rightfully concerned along with scientists themselves that the lack of a completely successful gene therapy program is very concerning. Scientists themselves feel that before additional clinical trials are conducted, more must be understood about the factors that control whether a particular vector can enter a given type of cell and become incorporated into its genetic material.
