Genetic Engineering – Basics, Examples, Techniques in Human

Basics of genetic engineering

Genetic engineering is the process of transferring specific genes from the chromosome of one organism and transplanting them into the chromosome of another organism in such a way that they become a reproductive part of the new organism. In Genetic Engineering, The process that produces the resulting recombinant DNA involves four steps:

  1. The desired DNA is cleaved from the donating chromosome by the action of restriction enzymes, which recognize and cut specific nucleotide segments, leaving a “sticky end” on both ends. The restriction enzymes also splice the receiving chromosome in a complementary location, again leaving “sticky ends” to receive the desired DNA.
  2. The desired DNA fragment is inserted into a vector, usually a plasmid, for transfer to the receiving chromosome. Plasmids are an ideal vector because they replicate easily inside host bacteria and readily accept and transfer new genes. Plasmids are circular DNA molecules found in the cytoplasm of bacteria that bond with the desired DNA fragment with the help of the joining enzyme, DNA ligase, to create the resulting recombinant DNA.
  3. When the host cell reproduces, the plasmids inside also reproduce, making multiple clones of their DNA. Because the plasmid DNA contains the desired as well as unwanted DNA clones, the entire product is referred to as a gene library. The desired gene is similar to one book in that library.
  4. To recover the desired DNA, the current technology is to screen unwanted cells from the mixture and then use gel electrophoresis to separate the remaining genes by movement on an electric grid. Gel electrophoresis uses a positively charged grid to attract the negatively charged DNA fragments, thereby separating them by size, because the smaller ones will migrate the most. Radioactive or fluorescent probes are added, which attract and bind with the desired DNA to produce visible bands. Once isolated, the DNA is available for commercial use.


Genetic engineering is accomplished in three basic steps. These are

  1. The isolation of DNA fragments from a donor organism;
  2. The insertion of an isolated donor DNA fragment into a vector genome and
  3. The growth of a recombinant vector in an appropriate host.

In Genetic Engineering, These steps are briefly reviewed and the part∗that they each play in a genetic engineering experiment is discussed.

Genetic engineering also called genetic modification or genetic manipulation is the direct manipulation of an organism’s genes using biotechnology. It is a set of technologies used to change the genetic makeup of cells, including the transfer of genes within and across species boundaries to produce improved or novel organisms. In Genetic Engineering, New DNA is obtained by either isolating and copying the genetic material of interest using recombinant DNA methods or by artificially synthesizing the DNA. A construct is usually created and used to insert this DNA into the host organism. The first recombinant DNA molecule was made by Paul Berg in 1972 by combining DNA from the monkey virus SV40 with the lambda virus. As well as inserting genes, the process can be used to remove, or “knock out”, genes. The new DNA can be inserted randomly or targeted to a specific part of the genome.
An organism that is generated through genetic engineering is considered to be genetically modified (GM) and the resulting entity is a genetically modified organism (GMO).
According to Genetic Engineering, The first GMO was a bacterium generated by Herbert Boyer and Stanley Cohen in 1973. Rudolf Jaenisch created the first GM animal through Genetic Engineering when he inserted foreign DNA into a mouse in 1974.
The first company to focus on genetic engineering – Genentech was founded in 1976 and started the production of human proteins. By Genetic Engineering, Genetically engineered human insulin was produced in 1978 and insulin-producing bacteria were commercialized in 1982.
Genetically modified food has been sold since 1994 Through Genetic Engineering, with the release of the FlavrSavr tomato. The FlavrSavr was engineered to have a longer shelf life, but most current GM crops are modified to increase resistance to insects and herbicides.
GloFish, the first GMO designed as a pet, was sold in the United States in December 2003. In 2016 salmon modified with a growth hormone were sold.
Genetic engineering has been applied in numerous fields including research, medicine, industrial biotechnology, and agriculture. According to Genetic Engineering, In research GMOs are used to study gene function and expression through loss of function, a gain of function, tracking, and expression experiments. By knocking out genes responsible for certain conditions it is possible to create animal model organisms of human diseases. As well as producing hormones, vaccines, and other drugs genetic engineering have the potential to cure genetic diseases through gene therapy. In Genetic Engineering, The same techniques that are used to produce drugs can also have industrial applications such as producing enzymes for laundry detergent, cheeses, and other products.
In Genetic Engineering, The rise of commercialized genetically modified crops has provided economic benefit to farmers in many different countries but has also been the source of most of the controversy surrounding the technology. This has been present since its early use; the first field trials were destroyed by anti-GM activists. Although there is a scientific consensus that currently available food derived from GM crops poses no greater risk to human health than conventional food, GM food safety is a leading concern with critics. According to Genetic Engineering, Gene flow, impact on non-target organisms, control of the food supply, and intellectual property rights have also been raised as potential issues. These concerns have led to the development of a regulatory framework, which started in 1975. It has led to an international treaty, the Cartagena Protocol on Biosafety, that was adopted in 2000. Individual countries have developed their own regulatory systems regarding GMOs, with the most marked differences occurring between the US and Europe.