Genetic engineering, genetic modification (GM) and gene splicing are terms for the process of manipulating genes, usually outside the organism's normal reproductive process.
It involves the isolation, manipulation and reintroduction of DNA into cells, usually to produce a new protein function. The aim is to introduce new characteristics or traits that affect the normal physiology or morphology of the final organism. Engineering crop resistant to a herbicide or mass producing a specific protein or enzyme and common examples that have reached the market. The production of human insulin through the use of modified bacteria, the production of erythropoietin (EPO) in Chinese hamster ovary cells (CHO) are two examples products routinely used for medicinal uses. Model systems for studying human diseases, such as the OncoMouse (cancer mouse), are routinely designed to have a higher susceptibility for a disease. This is often achieved by introducing a segment of DNA with a defective gene that is thought to be associated with the disease in humans.
Since a protein is specified by a gene, future versions any protein can be modified by changing the DNA sequence of the gene that encodes for that protein. One way to do this is to isolate the piece of DNA containing the gene, precisely cut the gene out, and then recombine the gene of interest with other fragments of DNA. This recombination of specific DNA fragments is critical for genetic engineering and a key resource for this was the isolation of restriction endonucleases, which are able to cut DNA at specific sites. For this discovery, Daniel Nathans and Hamilton Smith received the 1978 Nobel Prize in physiology or medicine and together with ligase, which can bond specific fragments of DNA together, this formed the basis for all future recombinant DNA technology.
The first Genetically Engineered drug was human insulin approved by the USA's FDA in 1982.[1] Another early application of GE was to create human growth hormone as replacement for a drug that was previously extracted from human cadavers. In 1986 the FDA approved the first genetically engineered vaccine for humans, for hepatitis B.[1] Since these early uses of the technology in medicine, the use of GE has expanded to supply many drugs and vaccines.
One of the best known applications of genetic engineering is that of the creation of genetically modified organisms (GMOs).
There are potentially momentous biotechnological applications of GM, for example oral vaccines produced naturally in fruit, at very low cost.
A radical ambition of some groups is human enhancement via genetics, eventually by molecular engineering. See also: transhumanism.
DNA sequencing is a technique which is used to identify each base in DNA. Although the costs of DNA sequencing has dropped dramatically, the NIH estimates it costs at least $10 million to sequence 3 billion base pairs[2]- the size of the whole human genome.
Although there has been a tremendous revolution in the biological sciences in the past twenty years, there is still a great deal that remains to be discovered. The completion of the sequencing of the human genome, as well as the genomes of most agriculturally and scientifically important plants and animals, has increased the possibilities of genetic research immeasurably. Expedient and inexpensive access to comprehensive genetic data has become a reality with billions of sequenced nucleotides already online and annotated. Now that the rapid sequencing of arbitrarily large genomes has become a simple, if not trivial affair, a much greater challenge will be elucidating function of the extraordinarily complex web of interacting proteins, dubbed the proteome, that constitutes and powers all living things. Genetic engineering has become the gold standard in protein research, and major research progress has been made using a wide variety of techniques, including: