Genetics is ... Genetics and health. Methods of Genetics

Genetics is a science that studies the patterns of the transmission of traits from parents to descendants. This discipline also considers their properties and the ability to change. In this case, special structures - genes - act as carriers of information. At present, science has accumulated enough information. It has several sections, each of which has its own tasks and objects of research. The most important of the sections are: classical, molecular, medical genetics and genetic engineering.

Classical Genetics

Classical genetics is the science of heredity. This property of all organisms transmit during their reproduction their external and internal signs to the offspring. Classical genetics also deals with the study of variability. It is expressed in the instability of symptoms. These changes accumulate from generation to generation. Only because of this inconstancy organisms can adapt to changes in their environment.

Hereditary information of organisms is contained in the genes. At present, they are considered from the point of view of molecular genetics. Although these concepts arose long before the appearance of this section.

The terms "mutation", "DNA", "chromosomes", "variability" became known in the course of numerous studies. Now the results of centuries-old experiences seem obvious, but once it all began with random crossings. People sought to get cows with large milk yields, larger pigs and sheep with thick wool. These were the first, not even scientific, experiments. However, it was these prerequisites that led to the emergence of such a science as classical genetics. Until the 20th century, crossing was the only known and accessible method of investigation. It is the results of classical genetics that have become a significant achievement of modern biology science.

Molecular Genetics

This is a section that studies all the laws that are subordinated to processes at the molecular level. The most important property of all living organisms is their heredity, that is, they are able from generation to generation to preserve the basic features of the structure of their organism, as well as patterns of exchange processes and responses to the impact of various environmental factors. This is due to the fact that at the molecular level, special substances record and retain all the information received, and then transmit it to the next generation during the fertilization process. The discovery of these substances and their subsequent study became possible due to the study of the structure of the cell at the chemical level. So were discovered nucleic acids - the basis of genetic material.

The discovery of "hereditary molecules"

Modern genetics knows practically everything about nucleic acids, but, of course, it was not always so. The first assumption that chemicals can be somehow connected with heredity, was put forward only in the 19th century. The study of this problem at that time engaged biochemist F. Misher and the biological brothers of Gertwigi. In 1928, the domestic scientist NK Koltsov, basing himself on the results of research, suggested that all the hereditary properties of living organisms are encoded and located in giant "hereditary molecules." At the same time he stated that these molecules consist of ordered links, which, in fact, are genes. This was definitely a breakthrough. Koltsov also determined that these "hereditary molecules" are packed in cells into special structures called chromosomes. Subsequently, this hypothesis was confirmed and gave impetus to the development of science in the 20 th century.

The development of science in the 20th century

The development of genetics and further research led to a number of equally important discoveries. It was found that each chromosome in the cell contains only one huge DNA molecule, consisting of two strands. Its numerous segments are genes. Their main function is that they specifically encode information on the structure of protein-enzymes. But the realization of hereditary information in certain signs takes place with the participation of another type of nucleic acid - RNA. It is synthesized on DNA and removes copies from genes. It also transfers information to the ribosomes, where the synthesis of enzyme proteins occurs. The structure of DNA was elucidated in 1953, and RNA - in the period from 1961 to 1964.

From that time, molecular genetics began to develop in leaps and bounds. These discoveries became the basis of research, as a result of which the patterns of the deployment of hereditary information were revealed. This process is carried out at the molecular level in cells. Also, fundamentally new information on the storage of information in genes was obtained. Over time, it was established how DNA duplication mechanisms occur before cell division (replication), processes of information reading by the RNA molecule (transcription), synthesis of protein-enzymes (translation). Also, the principles of heredity change were discovered and their role in the internal and external environment of cells was clarified.

Decoding the structure of DNA

Methods of genetics intensively developed. The most important achievement was the decoding of chromosomal DNA. It turned out that there are only two types of sections of the chain. They differ from one another in the location of nucleotides. In the first type, each site is peculiar, that is, it is unique. The second contained a different number of regularly repeated sequences. They were called repetitions. In 1973, it was established that unique zones are always interrupted by certain genes. The segment always ends with a repetition. This gap encodes certain enzymatic proteins, it is for them to "orient" RNA when reading information from DNA.

The first discoveries in genetic engineering

Emerging new methods of genetics led to further discoveries. A unique property of all living matter was revealed. It's about the ability to repair damaged areas in the DNA chain. They can arise as a result of various negative influences. The ability to self-repair was called "the process of genetic repair". At present, many eminent scientists express quite hopeful facts about the possibility of "snatching" certain genes out of the cell. What can this give? First of all, the ability to eliminate genetic defects. Genetic engineering deals with such problems.

The replication process

Molecular genetics studies the processes of transmission of hereditary information during reproduction. The preservation of the invariability of the record encoded in the genes is ensured by its accurate reproduction during cell division. The whole mechanism of this process is studied in detail. It turned out that just before division occurs in the cell, replication takes place. This is the process of DNA doubling. It is accompanied by an absolutely exact replication of the original molecules according to the complementarity rule. It is known that there are only four types of nucleotides in the strand of DNA. These are guanine, adenine, cytosine and thymine. According to the complementarity rule, discovered by scientists F. Krick and D. Watson in 1953, in the structure of the double chain of DNA adenine corresponds to thymine, and to the cytidyl nucleotide - guanyl. During the replication process, each DNA chain is replicated accurately by substituting the desired nucleotide.

Genetics is a relatively young science. The process of replication was studied only in the 50s of the 20th century. At the same time, the enzyme DNA polymerase was discovered. In the 1970s, after many years of research, it was established that replication is a multi-stage process. In the synthesis of DNA molecules, several different types of DNA polymerases directly participate.

Genetics and health

All information related to the dot reproduction of hereditary information during DNA replication processes is widely used in modern medical practice. The thoroughly studied regularities are characteristic of both healthy organisms and in cases of pathological changes in them. For example, it has been proven and confirmed by experiments that the cure of certain diseases can be achieved by influencing from outside the processes of replication of genetic material and the division of somatic cells. Especially if the pathology of the functioning of the body is associated with the processes of metabolism. For example, diseases such as rickets and impairment of phosphorus metabolism are directly caused by oppression of DNA replication. How can you change this state from the outside? Medications that stimulate oppressed processes have already been synthesized and tested. They activate DNA replication. This contributes to the normalization and recovery of pathological conditions associated with the disease. But genetic research does not stand still. Every year, more and more data is being received, helping not only to heal, but to prevent a possible disease.

Genetics and medicines

Molecular genetics is concerned with a lot of health issues. The biology of some viruses and microorganisms is such that their activity in the human body sometimes leads to a malfunction of DNA replication. It has also been established that the cause of some diseases is not the oppression of this process, but its excessive activity. First of all, these are viral and bacterial infections. They are caused by the fact that pathogenic microbes begin to multiply rapidly in affected cells and tissues. Also on this pathology are oncological diseases.

Currently, there are a number of drugs that can suppress DNA replication in the cell. Most of them were synthesized by Soviet scientists. These medicines are widely used in medical practice. These include, for example, a group of anti-tuberculosis drugs. There are antibiotics that suppress the processes of replication and division of pathological and microbial cells. They help the body to quickly deal with foreign agents, preventing them from multiplying. Such medications provide an excellent therapeutic effect in most serious acute infections. A particularly wide application of these tools found in the treatment of tumors and tumors. This is the priority direction that the Institute of Genetics of Russia has chosen. Each year, there are new improved drugs that hinder the development of oncology. This gives hope to tens of thousands of sick people around the world.

Transcription and translation processes

After the experimental laboratory tests on genetics were conducted and the results about the role of DNA and genes as matrices for the synthesis of proteins were obtained, for some time scientists were of the opinion that amino acids assemble into more complex molecules immediately, in the nucleus. But after receiving new data it became clear that this is not so. Amino acids are not built on gene sites in DNA. It was found that this complex process proceeds in several stages. First, exact copies - information RNAs - are removed from the genes. These molecules emerge from the nucleus of the cell and move to special structures - ribosomes. It is on these organelles that the assembling of amino acids and the synthesis of proteins occur. The process of obtaining copies of DNA was called "transcription." A synthesis of proteins under the control of information RNA - "translation". The study of the exact mechanisms of these processes and the principles of their influence are the main modern problems in the genetics of molecular structures.

The importance of transcription and translation mechanisms in medicine

In recent years, it has become apparent that scrupulous consideration of all stages of transcription and translation is of great importance for modern healthcare. The Institute of Genetics of the Russian Academy of Sciences has long confirmed the fact that with the development of almost any disease, intensive synthesis of toxic and simply harmful proteins is observed for the human body. This process can take place under the control of genes that are inactive in the normal state. Either this is the introduced synthesis, for which pathogenic bacteria and viruses penetrate into cells and tissues of a person. Also, the formation of harmful proteins can stimulate actively developing oncological neoplasms. That is why a thorough study of all stages of transcription and translation is extremely important now. So you can identify ways to fight not only with dangerous infections, but also with cancer.

Modern genetics is a continuous search for mechanisms of the development of diseases and drugs for their treatment. It is now possible to inhibit translation processes in the affected organs or the body as a whole, thereby suppressing inflammation. In principle, it is on this and the action of most known antibiotics, for example, tetracycline or streptomycin series, is constructed. All these drugs selectively inhibit the translation processes in cells.

The importance of researching the processes of genetic recombination

Of great importance for medicine is also a detailed study of the processes of genetic recombination, which is responsible for the transfer and exchange of chromosome regions and individual genes. This is an important factor in the development of infectious diseases. Genetic recombination underlies the penetration into human cells and the introduction into the DNA of an alien, often viral, material. As a result, the synthesis of proteins on the ribosomes is not "native" to the organism, but pathogenic for the organism. This principle is the reproduction in cells of whole colonies of viruses. Methods of human genetics are aimed at developing tools to combat infectious diseases and to prevent the assembly of pathogenic viruses. In addition, the accumulation of information on genetic recombination made it possible to understand the principle of gene exchange between organisms, which led to the appearance of genetically modified plants and animals.

The importance of molecular genetics for biology and medicine

For the last century, discoveries first in the classical, and then in molecular genetics have had a huge, and even decisive influence on the progress of all biological sciences. Especially strongly stepped forward medicine. The success of genetic research has made it possible to understand the once incomprehensible processes of inheritance of genetic traits and the development of individual characteristics of man. It is also remarkable how fast this science from purely theoretical to practical development. It became the most important for modern medicine. A detailed study of molecular-genetic patterns served as a basis for understanding the processes occurring in the body of both the patient and a healthy person. It was genetics that gave impetus to the development of such sciences as virology, microbiology, endocrinology, pharmacology and immunology.