GENETIC MANIPULATION Ever since man the hunter and gatherer gave up his nomadic way of life and began to tend stock and grow crops, he has been involved with genetic manipulation. Firstly, in ignorance, simply by choosing to rear particular animals or plants which were in some way advantageous to his developing lifestyle, and then much later, since the science of genetics began to develop, man has been engaged in breeding programs designed to produce varieties of plants and animals exhibiting the specific characteristics which fit them to his various needs. As mans exploitation of natural resources has continued and industries have developed based on the synthetic ability of micro-organisms, particularly the bacteria and fungi, his need for knowledge of the fundamental principles of the genetics of these organisms has increased and the new science of molecular genetics has emerged. The discipline seeks to understand the molecular base of inheritance and the way in which the information encoded by deoxy-ribonucleic acid (DNA) is utilized by the living cell. Advances in the field of recombinant DNA research over the past decade have given the geneticist the techniques required to mobilize individual genes, that is, specific sequences of DNA which code the amino acid structure of single proteins, and then transfer these genes from a donor to a recipient organism, thus conferring on the recipient the ability to synthesize the gene product. This is the practice of genetic manipulation as we understand the term today, which has become a cornerstone of the new Biotechnology. Scientists dont have to search in nature for wild micro-organisms capable of producing specific products through long, tedious and sometimes unrewarding processes any more, as they are now able to tailor microbial hosts for specific purposes by introducing foreign genes into them. The source of this foreign DNA can be microbial, animal, or plant and thus microbial hosts can be converted into biosynthetic factories capable of making a wide diversity of materials needed in every aspect of our lives from food and fuel to agriculture and medicine. Most recombinant DNA experiments are designed to transfer specific genetic information from a donor organism to a recipient cell so that the newly acquired gene will be activated and will result in the production of a foreign protein. In order to do this, the DNA to be transferred must first be isolated from the donor organism and inserted into a DNA carrier or vector molecule which will be used to transfer it into its new host. Fragments of DNA can be cut out of large DNA molecules, present in the chromosomes of plants and animals, and inserted into vectors with great ease owing to the discovery of a group of enzymes known as restricted endonucleuses. These enzymes recognize specific base sequences on DNA molecules and cut them precisely within or near that sequence. There are currently some three hundred of these enzymes known and some forty or so are commercially available in a highly-purified form. There is an enormous growth of interest and input of capital into researching the applications of recombinant DNA research over the past decade. This proves the potential benefits these techniques can provide. Recombinant DNA technology is obviously useful in fundamental research in molecular genetics, a field which has provided and will continue to provide invaluable information to both academic and applied geneticists. In fact, it has already made important contributions in several areas of applied science.
Posted on: Fri, 19 Dec 2014 20:30:00 +0000
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