Genetic engineering (Recombinant DNA technology or rDNA technology) is the deliberate, controlled manipulation of the genes in an organism with the intent of making that organism better in some way. This is usually done independently of the natural reproductive process. The result is a so-called genetically modified organism (GMO). To date, most of the effort in genetic engineering has been focused on agriculture. Genetic engineering has numerous benefits, including the production of food-bearing plants that are resistant to extreme weather and adverse climates, insect infestations, disease, molds, and fungi. A major motivation is the hope of producing abundant food at low cost to reduce world hunger, both directly (by consuming GMOs to human beings) and indirectly (by feeding GMOs to livestock and fish, which can in turn become food to humans. GMO s are being widely used for producing recombinant proteins for human and animal therapeutic uses.
Genetic modification is basically carried out by manipulating the genetic material, DNA of the organism or cell. In all organism proteins are coded by genes which are segments of DNA. There are certain enzymes which can specifically cut the DNA sequences at specific sites. These are called restriction enzymes. Using restriction enzymes, a target site of the recipient DNA is cleaved and a new set of sequence of DNA ( gene of interest)can be introduced to this cleaved site and ligated. The enzymes which join the DNA fragments are generally termed as ligases. The new chimeric DNA can be propagated and can be expressed in cell lines or bacteria to produce the gene of interest which had been introduced into that recipient DNA. Usually plasmid DNA vectors are used to clone gene of interest into it and then amplified in a bacteria in large quantities. Later these chimeric plasmids are transfected (mammalian cells) or transformed (bacteria) to yield the protein from the gene of interest in large quantities.
Genetic engineering carries potential dangers, such as the creation of new allergens and toxins, the evolution of new weeds and other noxious vegetation, harm to wildlife, and the creation of environments favorable to the proliferation of molds and fungi. Evolution of new disease organisms and increased antibiotic resistance could result from the use of GMOs in the food chain.
Reference:
- Molecular Biology of the Cell: Bruce. Alberts, Dennis Bray, Julian Lewis, Martin Raff, Keith Roberts – 1989
- Molecular Cell Biology. 4th ed.
- Lodish, Harvey; Berk, Arnold; Zipursky, S. Lawrence; Matsudaira, Paul; Baltimore, David; Darnell, James E. New York: W. H. Freeman & Co.; c2000.