International abbreviation for the English name deoxyribonucleic acid. The German short name DNS (deoxyribonucleic acid) is hardly used anymore 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 received the Nobel Prize for Medicine in 1962 with Maurice Wilkins (1916-2004).
The name derives from the basic DNA building blocks deoxyribose (one consisting of five carbon atoms zuckerart, a pentose ), Phosphoric acid and four bases that make up the nucleic acid. DNA is a chain molecule in the cell nuclei of all plant, animal and human organisms, which serves as a 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 them directly, but instead have "service organs" for them, the proteins.
The entire genome is called a genome, whereas a gene is a small section of DNA with different dimensions. It took 25 scientists from the Sequence Ontology Consortium at the University of Berkeley two days to try to find a current definition of the gene in early 2006: A gene is a localizable region of genomic DNA sequence that corresponds to a hereditary unit and is associated with regulatory, transcribed and / or functional sequence regions is. It contains basic information for the development of properties of an individual 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, which is made up of two opposite DNA single strands in the form of a screw-twisted rope ladder, which is also called a double helix. These are called chromosome (Colored body). This can be thought of as an extremely long, thin rope ladder. The length of the DNA in a human cell is just under two meters. Since a human being consists of around 100 trillion cells (25% of which are blood cells that do not have a nucleus), the total length of DNA in a human being is 150 billion kilometers, i.e. 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 rungs consist of two of the four bases. These are A denin, G uanin, C ytosin and T hymin. Of these four building blocks, two always fit together like a key and lock - A and T form one pair, C and G the other. For example, if “TAACGCCCTTA” is on one strand, the other strand is “ATTGCGGGAAT”.
A phosphoric acid ester and a sugar unit form the backbone of a molecule (part of the blue band). Together with a base, these three units form a nucleotide (red ellipses). The two nucleotides (ellipses) together form a macromolecule of the nucleic acid type deoxyribonucleic acid. In addition to their function as an information store, the nucleic acids that are considered “key molecules of life” can also serve as signal transmitters or catalyze (support) biochemical reactions.
The ladder can be called the “gene alphabet”, with the order of the base pairs playing an extremely important role. The gene code is read (decoded) by the cell and the proteins are built up. Proteins ( proteins ) consist of amino acids. The individual proteins have very specific tasks. The sequence of the base pairs determines how proteins are composed and how the organism is made up with all details. In humans, they determine the appearance (e.g. body size, hair and eye color) and properties (e.g. temperament, cause of illness and also the talent or potential for a certain sport). However, environmental influences play an equally important role in growing up. It is not yet clear whether genetics or the environment play a more important role. The only thing that is clear is that there is an interaction and that properties play a greater role at one time and another at another.
The DNA in the human genome is divided into 23 chromosomes (n = 23), which are duplicated (homologous) (2n = 46). One of the two chromosomes comes from the mother or the father. When the genome is passed on to the next generation, the mother only passes one of her two chromosomes on to the child. Together with the father's simple set of chromosomes, a new diploid chromosome mixture is created. In addition, individual sections can be exchanged during the inheritance process (crossing over), so that everyone has an exclusive genome pattern.
Humans have 20,000 to 25,000 genes (the exact number is still unknown), but the water flea, interestingly, 30,000. It is not the number that counts, but the interconnection and interaction of the genes. Incidentally, the DNA of all people is 99.9% identical despite all individuality and uniqueness. The difference is only 0.1%, which can mean big differences in appearance and skills. There is less agreement between chimpanzees and orangutans than with 99% between chimpanzees and humans (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 a completely insignificant detail). This is why the term "race", which is no longer relevant or used in science, is obsolete. Incidentally, the DNA is right grapevine 50% match that of humans. In principle, this applies to many plants. Many processes such as B. Metabolic processes are identical in humans, animals and plants.
This phenomenon of a pronounced heterozygosity (also mixed character, split character, inequality) is the reason for the individual appearance of each individual person, and is to the same extent for varieties typical. Through spontaneous mutations there are small changes in the genetic information that are passed on to the offspring and lead to the splitting of traits into many variants (alleles). Also cloned vines that come from vegetative propagation of a mother stock can develop due to mutations in the genetic material, which is particularly the case with very old and highly propagated grape varieties such as Gouais Blanc (Heunisch) muscatel. Pinot and Traminer has occurred frequently.
All varieties of the Vitis subgenus 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.). Because of the same number of chromosomes and nonexistent crossing barriers, these can be found in the breeding cross new grape varieties largely without problems. But there are also vine species like the American one Vitis rotundifolia with a different number of chromosomes (n = 20, 2n = 40). If these are crossed with species of the subgenus Vitis, there are no or only sterile offspring (2n = 39).
The genetic information at certain gene locations (microsatellites) within the DNA chain is used to identify or compare grape varieties. Six to eight microsatellites are usually sufficient to identify grape varieties. However, in order to be able to reliably prove lineages or family relationships, about 25 gene locations are required. In the molecular Genetics such sections are called "fingerprints". In the breeding resistant grape varieties have been using the not uncontroversial manipulative for some time genetic engineering (Genetic engineering). This involves introducing foreign genes with desired properties into the genome of plant cells of certain conventional varieties. In 2002 the institute developed a method to identify adulterated wines and to define the percentage of different grape varieties in a wine 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 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 are available in 89 variants. That is also the reason for the many different ones flavorings of wine. The comparison with other genomes also shows which plants the grapevine Is related. According to this, the grapevine genome is composed of three previous genomes and is more closely related to the poplar than to the rice. Knowledge of the genome could also be helpful for pathogens by going through genetic engineering resistance causes. See bez. Descent of a grape variety under molecular Genetics, related Taxonomy under Vines systematics as well as Vine-relevant keywords under grapevine,
Sources: Onmeda , Simlpy Science and WIKIPEDIA deoxyribonucleic acid
Animated double helix: By Zephyris , CC BY-SA 3.0 , Link
Grapes and glasses: By Photo Mix from Pixabay
Human heads: By collective, CC BY-SA 3.0 , Link
Chimpanzee: By suju from Pixabay
Grape varieties: Ursula Brühl, Doris Schneider, Julius Kühn-Institut (JKI)