Internationally common abbreviation for the English term deoxyribonucleinacid. The German abbreviation DNA (deoxyribonucleic acid) is hardly used any more to avoid confusion with the Domain Name System (DNS) of the Internet. The structure of DNA was elucidated in 1953 by the biologists James Watson (* 1928) and Francis Crick (1916-2004), who in 1962 were awarded the Nobel Prize for Medicine with Maurice Wilkins (1916-2004).
The name derives from the basic DNA building blocks deoxyribose (one of five carbon atoms zuckerart, one pentose ), Phosphoric acid and four bases which give the nucleic acid. The DNA is a chain molecule in the cell nuclei of all plant, animal and human organisms, which serves as the carrier of genetic information for the maintenance of all biological life processes and is inherited. The genes are responsible for every single function in an organism, such as cell division or metabolism. However, they do not exercise these directly, but instead have, so to speak, "service organs", the proteins.
The whole genome is called a genome, whereas a gene is a small portion of the DNA of varying degrees. In early 2006, 25 scientists from the Sequence Ontology Consortium of Berkeley University needed two days to attempt an up-to-date definition of the gene: A gene is a localizable region of genomic DNA sequence that corresponds to a genetic unit and associates with regulatory, transcribed, and / or functional sequence regions is. It contains basic information for the development of an individual's traits and for the production of a biologically active RNA (ribonucleic acid). An essential function of RNA in the biological cell is the conversion of genetic information into proteins.
The genes form a long chain molecule composed of two opposing DNA strands in the form of a twisted rope ladder, which is also called double helix. These are called chromosome (Color body). This can be thought of as an extremely long, thin rope ladder. The length of DNA in a human cell is just under two meters. Since a person consists of around 100 trillion cells (25% of them are blood cells that do not have a cell nucleus), the total length of DNA in a human being is 150 billion kilometers, ie around 1,000 times the distance from the earth to the sun with around 150 million Kilometre.
The two outer rods of the ladder consist of phosphoric acid and sugar molecules (deoxyribose). The connection of the pairs is the "rung", the sides of the ladder are called "strands". The sprouts each consist of two of the four bases. These are hymin A denin, G uanin, C and T ytosin. Of these four building blocks, two always fit together like keys and locks - A and T make one pair, C and G the other. For example, if one string is "TAACGCCCTTA", then the other string is "ATTGCGGGAAT".
A phosphoric acid ester and a sugar moiety form the backbone of a molecule (part of the blue band). Together with a base, these three units form one nucleotide (red ellipses). The two nucleotides (ellipses) together give a macromolecule of the nucleic acid type deoxyribonucleic acid. In addition to their function as information storage, the nucleic acids known as "key molecules of life" can also serve as signal carriers or catalyze (support) biochemical reactions.
You can call the ladder a "gene alphabet", with the order of the base pairs playing a very important role. The gene code is read (decrypted) by the cell and used to build up the proteins. Proteins ( proteins ) consist of amino acids. The individual proteins have very specific tasks. The sequence of base pairs dictates how proteins assemble and how the organism is made up with all the details. In humans, they determine the appearance (eg height, hair and eye color) and characteristics (eg temperament, cause of illness and also the talent or potential for playing the piano).
The DNA in the human genome is subdivided into 23 chromosomes (n = 23), which occur in duplicate (homologous) versions (2n = 46). One of each of the two chromosomes comes from the mother or father. When the genome is passed on to the next generation, the mother gives only one of her two chromosomes to the child. Together with the father's simple set of chromosomes, a new diploid chromosome mixture is created. In addition, during the inheritance process, individual sections can still be exchanged (crossing over), so that each person has an exclusive genome pattern.
Humans have 20,000 to 25,000 genes (the exact number is still unknown), while the water flea is interestingly 30,000. It does not depend on the number, but on the interconnection and interaction of the genes. Incidentally, despite all individuality and uniqueness, the DNA of all human beings agrees 99.9%. The difference is only 0.1%, which can mean big differences in appearance and ability. There is less agreement between chimpanzees and orangutans than between chimpanzees and humans at 99% (but the differences are ten times greater than between two humans). A European and a black African can be more similar than two Europeans (the color of the skin is an insignificant detail). That is why the term "race", which is no longer relevant or used in science, is obsolete. By the way, the DNA is right grapevine 50% of people's. This applies in principle to many plants. Many processes such. B. Metabolic processes are identical in humans, animals and plants.
This phenomenon of a pronounced heterozygosity (Also mixed, gap, unevenness) is the reason for the individual appearance of each individual, and is equally for varieties typical. By spontaneous mutations There are small changes in the genetic information, which are passed on to the offspring and lead to the splitting of features into many variants (alleles). Also cloned vines coming out vegetative propagation derive from a parent strain, can diverges due to mutations in the genetic material, which is particularly the case of very old and greatly propagated grape varieties such as Gouais blanc (Heunisch) muscatel. Pinot and Traminer often occurred.
All varieties of the vine subgenus Vitis have a diploid (double) chromosome set with 2x19 chromosomes (n = 19, 2n = 38). These are all Asians Vines (such as. Vitis amurensis. Vitis coignetiae Etc.), Europeans Vines (Vitis vinifera) and most American vines (such as. Vitis cinerea. Vitis riparia. Vitis rupestris. Vitis labrusca Etc.). Due to the same number of chromosomes and non-existent crossing barriers, this can be found in the breeding largely cross new grape varieties easily with each other. But there are also vine species like the American one Vitis rotundifolia with different numbers of chromosomes (n = 20, 2n = 40). Crossing these with species of the subgenus Vitis, no or only sterile offspring arise (2n = 39).
For identification or comparison between grape varieties one uses the genetic information at certain gene locations (microsatellites) within the DNA chain. Six to eight microsatellites are usually sufficient for the identification of grape varieties. However, in order to be able to reliably prove descent or family relationships, you need about 25 loci. In the molecular Genetics Such sections are called fingerprints. In the breeding resistant grape varieties has been used for some time now not disputable manipulative genetic engineering (Genetic engineering). In this case, foreign genes with desired properties are introduced into the genome of plant cells of certain conventional varieties. For the detection of wine spoilage and for the definition of the percentage of different grape varieties in a wine was 2002 by the Institute INRA the procedure Nuclear Magnetic Resonance developed.
In August 2007, the deciphering of the grapevine genome was announced by Italian and French researchers. It is thus the first fruit-bearing plant whose DNA sequence is known. The scientists discovered some peculiarities. That for the production of resveratrol competent enzyme Stilbene (an aromatic hydrocarbon) is present 43 times in the genome. The gene for the formation of the flavor terpene There are 89 variants. That is also the cause of the many different ones flavorings of the wine. The comparison with other genomes also shows with which plants the grapevine Is related. According to this, the grapevine genome consists of three predecessor genomes and is more closely related to the poplar than to the rice. Knowledge of the genome could also be helpful in pathogens by going through genetic engineering resistance causes. See bez. Descent of a grape variety under molecular Genetics, bez. Taxonomy under Vines systematics as well as bez. varietal relevant keywords under grapevine,
Sources: Onmeda , Simlpy Science and WIKIPEDIA deoxyribonucleic acid
Double Helix Animated: By Zephyris , CC BY-SA 3.0 , Link
Grapes and Glasses: From Photo Mix on Pixabay
Human Heads: From Collective, CC BY-SA 3.0 , Link
Chimpanzee: From suju on Pixabay
Grape varieties: Ursula Bruehl, Doris Schneider, Julius Kühn Institute (JKI)