Genetic engineering
Insulin with the help of genetic engineering
Over 300,000 people in Germany suffer from diabetes . They need insulin , a hormone that is now being produced by genetic engineering. Insulin is made by the islets of Langerhans in the pancreas produced, it ensures the regulation of the sugar level. If the hormone fails, this leads to the clinical picture of diabetes. Human insulin is the first drug to be genetically engineered. For 15 years, the hormone that is vital for diabetics has been able to be produced without extracting it from the pancreas of slaughtered cattle or pigs. With the help of genetic engineering, the blueprint for insulin was isolated from human cells and transferred to bacteria or yeast. In large stirred tanks, so-called fermenters, the microorganisms multiply and produce human insulin. Genetically engineered insulin is therefore absolutely free of pathogens from animals.
Difficult terms: gene, genome and genetic engineering
The gene is the smallest unit of genetic material (genetic material is also called genome, i.e. the totality of all genes of an organism). Our genome contains between 30,000 to 40,000 genes; that is only about 300 more genes than the mouse and about twice as many as the fruit fly. About 9,000 human genes have already been identified. Genetic engineering includes all biological-technical processes that specifically change the genetic material of a cell. The genetic information is stored in a gigantic molecule called deoxyribonucleic acid, for which the abbreviation DNA has come into use in scientific parlance (after the English term deoxyribonucleid acid).
The principle of genetic engineering: Sections of foreign DNA are introduced into the cell in order to bring about defined changes there. The well-known example is the human insulin drug produced in this way. In the genetic engineering of medicines, genes that code for substances that can be used therapeutically are transferred into cells that are as easy as possible to cultivate. Bacteria are ideal for this, and more rarely also yeast and mammalian cells. With the help of genetic engineering, new medicines such as human insulin, vaccines such as a remedy for hepatitis B and diagnostics were created that are already being used worldwide.
The approval of medicines that are manufactured with the help of genetically modified organisms is regulated by the Medicines Act and the Animal Diseases Act. In addition, an approval under the Genetic Engineering Act must be available. An essential task of human genome research is to identify which genes are involved in the development of diseases and how. From this, the scientists expect new concepts for the treatment of cardiovascular diseases, cancer , infectious diseases or diseases of the nervous system such as Parkinson’s disease, multiple sclerosis or Alzheimer’s disease.
The Cloned Sheep
Scottish scientists succeeded in cloning a sheep in 1996 after removing the udder cell from a six-year-old sheep and inserting it into a previously enucleated egg cell. Dolly, the copy of another sheep, a marvel of science, the flesh-and-blood artifact, had been created from the genome of a body cell. But as early as mid-1999, it was found that Dolly’s genetic makeup looked unusually old – Dolly recently had to be put down. However, cloning does not alter the genetic material. Cloning is generally understood to mean the artificial production of genetically identical living beings. For example, all the bacteria in a colony are naturally genetically identical; in humans, the identical twins are a special case.
Green genetic engineering
One area of application for so-called green genetic engineering is the production of food. Experts estimate that between 50 and 70 percent of our food in Germany has come into contact with genetic engineering. The spectrum of genetically modified products ranges from the enzymes and flavorings for our bread to anti-mushy tomatoes and fungus-resistant red wine to performance-enhanced dairy cows. One examines the use of genetic modifications, for example in biological pest control using genetically modified viruses or to improve the quality of plant products, for example in food to improve shelf life, storability, tolerability, nutritional value and taste. Not only animals and plants that are used directly as food are genetically modified, but also microorganisms that change and refine food. Examples are the classic biological processes of beer and wine production or the maturing of cheese .
hope gene therapy
Gene therapy uses all methods that are used to directly influence the genetic material for medical purposes. Gene therapy measures are already being used to treat hereditary diseases and cancer. There are great hopes here, which are cautious and long-term, and are based on being able to use this understanding for better therapies for certain diseases. If, for example, it is possible to identify genes that are involved in the development of diseases, ideally new drugs could be developed that combat the causes and not just the symptoms.
Stem cell treatment in the womb
With a stem cell treatment in the womb, Californian scientists have for the first time succeeded in curing a hereditary disease before birth. Immunodeficiency is a disease in which newborns have no defenses against bacteria and therefore have to live in a germ-free tent for the first few years of life. For this purpose, healthy stem cells from the umbilical cord blood of another baby were injected into the unborn child before the 16th week of pregnancy . Stem cells are precursors of differentiated and thus specialized cells. In the bone marrow, for example, there are stem cells for the cells found in the blood, such as lymphocytes .
Stem cells from embryos can develop into a complete organism (then one speaks of totipotency). Stem cells with a very low degree of maturity are also found, albeit in very small numbers, in adult tissues such as the liver, kidneys, brain or in the umbilical cord blood of newborns. They could serve as an alternative to embryonic stem cells – this is currently the subject of research. With stem cell transplantation, the researchers were able to heal the immune deficiency in the womb for the first time. Therefore, the injected, healthy cells can take the place of the body’s own cells. When the healthy cells settle in the baby’s body, the missing enzyme is replaced and the defect is eliminated.
The human genome has been largely decoded. This is considered a milestone in human history. But it is precisely here that new demands are made on science, politics and ethics. Ethics is required to show whether and how these findings can be used responsibly in areas as diverse as medicine and agriculture.