Invisible enemies
What unites albinos, Ninja Turtles and antibiotic-resistant bacteria ? They are all mutants. However, mutations are different mutations: changes in DNA are different. If the metamorphosis is random and the action does not occur in the comic, then it is usually neutral. There are many reasons for the development of mutations, and we decided to focus on those that occur in real life. What are mutagens, how they were found, how they are dangerous and how to protect against them - in the new material Genotek.
DNA that carries the information of all living things is an instruction for the construction and functioning of the body. This is the case when "it does not matter how the code is written - the main thing is that it works." Sometimes events happen like mutations. Under mutation in biology is commonly understood as a change in genetic material. As a rule, organisms with so-called harmful mutations are “rejected” (die). However, sometimes the mutation is fixed and inherited. There are spontaneous mutations that can occur when molecular machines fail to work. For example, an error may occur during replication — doubling — or when repairing a molecule. These are internal causes of problems, they need to be dealt with separately. Mutagens are treacherously generated by the body itself or come from outside, they are not immediately noticeable, and the result of their impact is sometimes very scary.
')
The DNA molecule - the famous "double helix" - has regular parameters that allow you to keep the code available for reading and playback. Mutagens are physical or chemical agents that provoke the formation of irreversible structures, thus increasing the frequency of mutations. The latter sometimes lead to carcinogenesis, therefore a significant amount of mutagens are also carcinogenic. Physical mutagens are represented by different types of radiation and elevated temperature, which breaks the double helix itself or leads to numerous breaks. Chemical mutagens can either break the chain or be embedded inside the helix.
Chemical mutagens were first discovered in the forties of the last century: they were discovered by Charlotte Auerbach at the University of Edinburgh and Iosif Abramovich Rappoport at the Institute of Genetics of the Academy of Sciences of the USSR. Scientists were colleagues and warmly communicated. The forties in the USSR were tragic for Soviet genetics. In 1948, the August session of the Academy of Agricultural Sciences was held, at which Rappoport opposed Lysenko’s ideas, denying the conclusions of the session. In 1949, this led to Rappoport being expelled from the party. In 1962, the Nobel Committee planned to award the award to Rappoport and Auerbach. In order to avoid unpleasant consequences *, the committee appealed to the CPSU Central Committee before the nomination. In the department of science, Joseph Abramovich was offered to re-join the party to approve the nomination, but he insisted that his expulsion be invalidated and reinstated while retaining his experience. This was denied to him, and in 1962, Rappoport and Auerbach were left without an award: it was handed to scientists who discovered the molecular structure of nucleic acids.
It is important to distinguish between DNA damage and mutagenesis. If you imagine cells as small plants, factories or companies, the core in which the DNA is stored is the head office of the enterprise. From time to time, on the eve of some large-scale events, there is a rush job, but one way or another everything falls into place: everyone follows one another and in case of that they help to correct mistakes. So, on the eve of cell division, DNA doubling is necessary. A DNA polymerase may incorrectly insert a nucleotide or other into the chain, but its error will be immediately corrected: this will not get into the DNA of the daughter cells. In this case, it is a replication error. The mutation, on the contrary, is a change in DNA, which for some reason was not corrected. Mutagens are agents from the outside, racketeers, spies, or provocateurs who can break into or secretly infiltrate their superiors and destroy all company documents. So begins mutagenesis.
In the next part of the article we will try to answer the two most important questions: who is to blame and what to do.
A mutagen of physical nature, which is particularly common in the equatorial region and in the areas of ozone holes, is ultraviolet light in the range of 260-280 nm. DNA bases absorb ultraviolet light in this range, which can lead to the rupture of the bond between two DNA strands. Free nucleotides are stitched in pairs with adjacent ones, as shown in the picture.
The formation of pyrimidine dimers under the action of UV radiation.
If this error remains uncorrected, protein synthesis and DNA replication becomes complicated many times - this is mutagenesis. Of course, a little sunshine will not hurt anyone: as you already learned in one of the previous materials , it stimulates the production of vitamin D. However, the formation of pyrimidine dimers is one of the main causes of melanoma. In addition, prolonged exposure to the sun is harmful to the eyes .
It has been proven that trace elements such as carotenoids, flavonoids, tocopherols and omega-3 unsaturated fatty acids help in building protection against UV radiation. The assimilation of nutrients containing these substances also has a genetic conditionality . On the one hand, it is very convenient, on the other - if you have low digestibility of vitamin A or lipid metabolism disorders, but you like to travel around the equator, it is better to make sure in advance.
Mutagens of chemical nature act more subtly and cynically - they disrupt the structure of DNA.
One of the most common mutagens are reactive oxygen species. The trick is that these active forms are generated during the most common chemical reactions that take place in the human body. There can be bewilderment, because oxygen is a gas that is contained in the atmosphere of our planet, it is associated with breath with full breasts, freshness and some other pleasant sensations from the advertising of washing powders.
The answer lies in the title. Oxygen oxidizes substances that it encounters on its way. Remember the hydrogen peroxide, which is poured on a broken knee - about the same thing happens on a cellular scale with the release of active oxygen forms. Reactive oxygen forms destroy the membranes of which living cells are built, pull out individual bases from the DNA chain and introduce breaks. Not only what they do is scary, but also how sophisticated it is. Since the release of ROS is carried out continuously, when the neutralizing mechanism breaks down, the cells are constantly bombarded with mutagens and die in agony.
Antioxidants are substances found in fresh berries and fruits, in green tea, nuts and red wine. They save us from oxidation and active radicals, translating them into an inactive form. In other words, antioxidants are such altruists. They go out, see hooligans destroying walls, and take a hit. Antioxidants have many wonderful properties, one of which is protection against aging. According to some hypotheses, aging is associated with the release of ROS. Legion is singled out separately - vitamin E is a collective name for several fat-soluble substances with antioxidant activity. When it enters the digestive system, the ingredients of vitamin E are selected in the liver, and already alpha-tocopherol enters the metabolism circle.
It is important to take into account their own genetic predisposition to the absorption of vitamins, since antioxidants, if they are consumed excessively, are harmful: they can interfere with the absorption of other trace elements.
The name belongs to a group of poisonous carcinogens produced by some types of mold. Aflatoxins are the answer to the children's question: “Why can't the ground and fallen leaves be eaten?”, To the adult question: “Why does tea have an expiration date?” And to the old question: “Why can't you eat moldy cereal?” When storage conditions are not met , on a product, as on a medium, mold fungi of the genus Aspergillus grow. Danger may lie in cereals, spices, nuts, tea, milk, eggs, meat, dried fruits, bread and industrial juices. Mold may grow as a result of improper or long-term storage, and flavoring will dampen the unpleasant smell. If a dose of aflatoxins is not lethal, but regular, this may be the cause for the development of cirrhosis and liver cancer. Products with aflatoxins are particularly dangerous for future mothers: in addition to general poisoning, aflatoxins can disrupt embryogenesis.
Be careful not to eat expired products. Try to thoroughly wash the food and prepare the food immediately before use. However, people with gluten intolerance, lactose, or caffeine with aflatoxin feel a little calmer: more than half of the products at risk are already excluded from their menu. Such a feature of eating behavior, like the habit of overeating, can be doubly harmful in this situation.
Benzene is a chemical compound, without which it is impossible to imagine modern life. It is a toxin and carcinogen, which is part of the oil and gasoline, and is also widely used in the manufacture of medicines, plastics, rubber and dyes. If you place a person in an enclosed space and gradually add benzene there, then at first he will feel euphoria. Then drowsiness, nausea, headache, muscle twitching will appear. If you leave the subject in this chamber for a long time, then he will die, but if you let him out, you can observe a whole complex of disorders caused by benzene poisoning. However, we are not interested in this. Benzene is often found in poor-quality cosmetic products and plastic products, that is, systematic poisoning with benzene in small quantities is not excluded, which can provoke the occurrence of various types of hemato-oncological diseases.
Niacin, folate and cobalamin are B vitamins, the deficiency of which is primarily noticeable with benzene poisoning. They are necessary for DNA repair. Often people get vitamins of this group with the meat of animals. You can learn more about which processes are influenced by B vitamins and how to diagnose their deficiency, please click here .
Take care of yourself. Enemies in the face of mutagens can be everywhere. When it comes to a healthy lifestyle, those who are trying to change everything on their own, have to balance between the mass of advice and common sense. The border is shaky and resist on it is more likely that he who knows himself and does not harm himself.
Irreversible code changes
DNA that carries the information of all living things is an instruction for the construction and functioning of the body. This is the case when "it does not matter how the code is written - the main thing is that it works." Sometimes events happen like mutations. Under mutation in biology is commonly understood as a change in genetic material. As a rule, organisms with so-called harmful mutations are “rejected” (die). However, sometimes the mutation is fixed and inherited. There are spontaneous mutations that can occur when molecular machines fail to work. For example, an error may occur during replication — doubling — or when repairing a molecule. These are internal causes of problems, they need to be dealt with separately. Mutagens are treacherously generated by the body itself or come from outside, they are not immediately noticeable, and the result of their impact is sometimes very scary.
')
Secret Change Agent
The DNA molecule - the famous "double helix" - has regular parameters that allow you to keep the code available for reading and playback. Mutagens are physical or chemical agents that provoke the formation of irreversible structures, thus increasing the frequency of mutations. The latter sometimes lead to carcinogenesis, therefore a significant amount of mutagens are also carcinogenic. Physical mutagens are represented by different types of radiation and elevated temperature, which breaks the double helix itself or leads to numerous breaks. Chemical mutagens can either break the chain or be embedded inside the helix.
Lysenko as a mutagen of Soviet science
Chemical mutagens were first discovered in the forties of the last century: they were discovered by Charlotte Auerbach at the University of Edinburgh and Iosif Abramovich Rappoport at the Institute of Genetics of the Academy of Sciences of the USSR. Scientists were colleagues and warmly communicated. The forties in the USSR were tragic for Soviet genetics. In 1948, the August session of the Academy of Agricultural Sciences was held, at which Rappoport opposed Lysenko’s ideas, denying the conclusions of the session. In 1949, this led to Rappoport being expelled from the party. In 1962, the Nobel Committee planned to award the award to Rappoport and Auerbach. In order to avoid unpleasant consequences *, the committee appealed to the CPSU Central Committee before the nomination. In the department of science, Joseph Abramovich was offered to re-join the party to approve the nomination, but he insisted that his expulsion be invalidated and reinstated while retaining his experience. This was denied to him, and in 1962, Rappoport and Auerbach were left without an award: it was handed to scientists who discovered the molecular structure of nucleic acids.
Not all breakage - mutations
It is important to distinguish between DNA damage and mutagenesis. If you imagine cells as small plants, factories or companies, the core in which the DNA is stored is the head office of the enterprise. From time to time, on the eve of some large-scale events, there is a rush job, but one way or another everything falls into place: everyone follows one another and in case of that they help to correct mistakes. So, on the eve of cell division, DNA doubling is necessary. A DNA polymerase may incorrectly insert a nucleotide or other into the chain, but its error will be immediately corrected: this will not get into the DNA of the daughter cells. In this case, it is a replication error. The mutation, on the contrary, is a change in DNA, which for some reason was not corrected. Mutagens are agents from the outside, racketeers, spies, or provocateurs who can break into or secretly infiltrate their superiors and destroy all company documents. So begins mutagenesis.
In the next part of the article we will try to answer the two most important questions: who is to blame and what to do.
K. W .: Ultraviolet radiation
A mutagen of physical nature, which is particularly common in the equatorial region and in the areas of ozone holes, is ultraviolet light in the range of 260-280 nm. DNA bases absorb ultraviolet light in this range, which can lead to the rupture of the bond between two DNA strands. Free nucleotides are stitched in pairs with adjacent ones, as shown in the picture.
The formation of pyrimidine dimers under the action of UV radiation.
If this error remains uncorrected, protein synthesis and DNA replication becomes complicated many times - this is mutagenesis. Of course, a little sunshine will not hurt anyone: as you already learned in one of the previous materials , it stimulates the production of vitamin D. However, the formation of pyrimidine dimers is one of the main causes of melanoma. In addition, prolonged exposure to the sun is harmful to the eyes .
C. D.: Fat soluble nutrients
It has been proven that trace elements such as carotenoids, flavonoids, tocopherols and omega-3 unsaturated fatty acids help in building protection against UV radiation. The assimilation of nutrients containing these substances also has a genetic conditionality . On the one hand, it is very convenient, on the other - if you have low digestibility of vitamin A or lipid metabolism disorders, but you like to travel around the equator, it is better to make sure in advance.
Mutagens of chemical nature act more subtly and cynically - they disrupt the structure of DNA.
K. V.: Active forms of oxygen
One of the most common mutagens are reactive oxygen species. The trick is that these active forms are generated during the most common chemical reactions that take place in the human body. There can be bewilderment, because oxygen is a gas that is contained in the atmosphere of our planet, it is associated with breath with full breasts, freshness and some other pleasant sensations from the advertising of washing powders.
The answer lies in the title. Oxygen oxidizes substances that it encounters on its way. Remember the hydrogen peroxide, which is poured on a broken knee - about the same thing happens on a cellular scale with the release of active oxygen forms. Reactive oxygen forms destroy the membranes of which living cells are built, pull out individual bases from the DNA chain and introduce breaks. Not only what they do is scary, but also how sophisticated it is. Since the release of ROS is carried out continuously, when the neutralizing mechanism breaks down, the cells are constantly bombarded with mutagens and die in agony.
C. D.: Antioxidants
Antioxidants are substances found in fresh berries and fruits, in green tea, nuts and red wine. They save us from oxidation and active radicals, translating them into an inactive form. In other words, antioxidants are such altruists. They go out, see hooligans destroying walls, and take a hit. Antioxidants have many wonderful properties, one of which is protection against aging. According to some hypotheses, aging is associated with the release of ROS. Legion is singled out separately - vitamin E is a collective name for several fat-soluble substances with antioxidant activity. When it enters the digestive system, the ingredients of vitamin E are selected in the liver, and already alpha-tocopherol enters the metabolism circle.
It is important to take into account their own genetic predisposition to the absorption of vitamins, since antioxidants, if they are consumed excessively, are harmful: they can interfere with the absorption of other trace elements.
K. Q. Aflatoxins
The name belongs to a group of poisonous carcinogens produced by some types of mold. Aflatoxins are the answer to the children's question: “Why can't the ground and fallen leaves be eaten?”, To the adult question: “Why does tea have an expiration date?” And to the old question: “Why can't you eat moldy cereal?” When storage conditions are not met , on a product, as on a medium, mold fungi of the genus Aspergillus grow. Danger may lie in cereals, spices, nuts, tea, milk, eggs, meat, dried fruits, bread and industrial juices. Mold may grow as a result of improper or long-term storage, and flavoring will dampen the unpleasant smell. If a dose of aflatoxins is not lethal, but regular, this may be the cause for the development of cirrhosis and liver cancer. Products with aflatoxins are particularly dangerous for future mothers: in addition to general poisoning, aflatoxins can disrupt embryogenesis.
C. D.: Develop observant and correct eating habits.
Be careful not to eat expired products. Try to thoroughly wash the food and prepare the food immediately before use. However, people with gluten intolerance, lactose, or caffeine with aflatoxin feel a little calmer: more than half of the products at risk are already excluded from their menu. Such a feature of eating behavior, like the habit of overeating, can be doubly harmful in this situation.
K. W .: Benzene
Benzene is a chemical compound, without which it is impossible to imagine modern life. It is a toxin and carcinogen, which is part of the oil and gasoline, and is also widely used in the manufacture of medicines, plastics, rubber and dyes. If you place a person in an enclosed space and gradually add benzene there, then at first he will feel euphoria. Then drowsiness, nausea, headache, muscle twitching will appear. If you leave the subject in this chamber for a long time, then he will die, but if you let him out, you can observe a whole complex of disorders caused by benzene poisoning. However, we are not interested in this. Benzene is often found in poor-quality cosmetic products and plastic products, that is, systematic poisoning with benzene in small quantities is not excluded, which can provoke the occurrence of various types of hemato-oncological diseases.
C. D.: Vitamins of group B
Niacin, folate and cobalamin are B vitamins, the deficiency of which is primarily noticeable with benzene poisoning. They are necessary for DNA repair. Often people get vitamins of this group with the meat of animals. You can learn more about which processes are influenced by B vitamins and how to diagnose their deficiency, please click here .
Take care of yourself. Enemies in the face of mutagens can be everywhere. When it comes to a healthy lifestyle, those who are trying to change everything on their own, have to balance between the mass of advice and common sense. The border is shaky and resist on it is more likely that he who knows himself and does not harm himself.
Source: https://habr.com/ru/post/373071/
All Articles