The viruses that live in bacteria are called bacteriophage. They inject their DNA into bacterium, leaving their protein envelope outside. Inside of the bacterium, the virus is a filament of nucleic acid that contains coded information for the synthesis of new virus particles, which can be released with the bacteria lyses. The genetic engineering came about from the observation of how viruses use cells of other organisms or bacteria to express their own genes. In that sense, the viruses can be considered genetic engineers. One of the first experiments of genetic engineering was carried out using a bacteriophage as a true Trojan horse, to introduce DNA from other organisms into the bacterium.
One of the requirements for genetic engineering experiments is the production of DNA fragments that contain the desired information. At the beginning of the molecular biology era, DNA used to be cleaved with vibration by ultrasound waves. One of the difficulties that scientists faced in those experiments was the random fashion in which the DNA fragmented. In 1970, however, Dr. W. Arber discovered that bacteria themselves possess a mechanism to specifically cut DNA at certain sequences. Bacteria produce proteins called restriction enzymes that cleave the DNA at specific recognition sites. It was only after the discovery of the restriction enzymes that genetic engineering became a reality. The restriction enzymes were developed as a defense mechanism of bacteria against viruses.
Viruses inject DNA into bacteria and use their bacteria as a mechanism for reproduction. The bacteria, however, develop a mechanism that fragments the exogenous DNA using restriction enzymes. The restriction enzymes recognize the foreign DNA by means of certain specific nucleotide sequences. Different enzymes recognize and cut the DNA at different sites. Using this knowledge, restriction enzymes became essential tools for the genetic engineer to cut DNA into fragments and build new genes. Hundreds of different restriction enzymes exist, many of which are frequently used in biotechnology.
Tags: Bio Technology, Bio Genetics, Genetic Engineering, Virus
1 comments:
Love your blog! Thank you for this one on viruses. Your clarity is wonderful.
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