Genetics develops faster and faster: each year of DNA research brings more discoveries than the previous one. It was included in medicine, psychology, anthropology, ecology and other areas and became the basis for understanding the nature of human. Genetics studies the basic mechanisms of heredity and variability — properties inherent in all organisms. This science has great prospects for the extension of a healthy and active human life.
Development of genetics
Despite the fact that heredity has been known for a long time, the nature of this process was a mystery. The first and simplest assumption was that the children of "mixed" features of both parents, so the children have something in common with mother and father. However, already the ancient Romans knew that this process should proceed in a different way.
In the middle of the XIX century, the experiments of the Austrian monk Gregor Mendel allowed to approach the modern understanding of the mechanism of heredity. On the example of his own observations of plants, he showed that the signs are not mixed, but are transmitted in the form of discrete (separate) units to the next generation.
The scientific community didn’t attach much importance to its discovery. It was only in 1900 that the botanists Hugh de Vries, Karl Erich Correns and Erich Chermak obtained results similar to Mendelian and confirmed his hypothesis. In 1909, those discrete units responsible for the transmission of heredity, the Danish biologist Wilhelm Ludwig Johansen called "genes", and in 1910, scientists were able to establish that the genes are in the chromosomes. The function of the chromosomes was further clarified in 1944, when it was established that hereditary information is contained in DNA.
At the beginning of the 21st century, the global human genome project was completed, where scientists from different countries joined their efforts to study DNA in detail. As a result of the study, about 25,000 genes were identified and described. Knowledge of the human genome has made an invaluable contribution to the development of medicine and biotechnology.
Modern genetics is an extensive tree-like structure of derivative disciplines. Its specialized sections have been considered as major independent sciences: human genetics, cytogenetics, nutrigenomics, molecular genetics, metagenomics, immunogenetics, ecological genetics, and others.
How genes work
To understand what DNA - deoxyribonucleic acid looks like, one can imagine a zipper twisted into a spiral. DNA is stored in the nucleus of each cell and contains information that makes the body as it is. Each half of the helix consists of mutually corresponding nucleic acids, which together form a pair of bases (there can be up to three billion of them in one cell). These regions of nucleotide sequences encoding functional products are called genes. The entire set of genes obtained at birth constitutes the human genotype, and all the hereditary material enclosed in a cell is called the genome.
DNA controlled lever of the body are proteins. The human body uses them to work the immune system, digest food, heal wounds, catalyze chemical reactions, provide communication between cells, and so for complex physiological interactions that ensure the health and life of the body. In order for protein synthesis to occur, the DNA is first “rewritten” (transcribed) into RNA (ribonucleic acid), then the information transferred (translated) into the protein. This process is called gene expression.
In addition to coding DNA (the one that synthesizes proteins), there are genetic “switches” in the body that turn genes on and off. Such non-coding DNA accounts for about 98% of all human DNA and is often referred to as “junk”. However it isn’t so useless and necessary for the regulation of the work of genes and the functioning of the whole organism.
We can say that genes are eternal. The life of a single DNA molecule is short, but each of them is able to manage its own reproduction: copy itself and continue to exist for millions of years. But genes can be changed by various external factors and human health depends on these changes (mutations) because they’re the reasons of many diseases.
Wonders of the genetic world
Human genes are like small computer programs embedded in man since ancient times. For example, the insulin receptor gene in adipose tissue served the ancestors well tens of thousands of years ago: it helped to store as many calories as possible in conditions of a constant lack of food. However there’s no need to escape from hunger today, so the gene does more harm than good: problems such as overweight and obesity develop with double speed. The modern computer era requires a person to update his genetic code, and scientists have already had the opportunity to change it.
Scientists see the possibility of victory over many serious diseases, including oncological ones, in genetics. Today, there are promising techniques of gene therapy against cancer: oncolytic viral, prodrug, immunotherapy, and stem cell therapy. Already today, technologies allow editing the information contained in DNA. This allows specialists to “remove” malicious genes and activate useful ones. They develop individual programs to significantly improve human health: such techniques as genomic analysis, gene therapy and molecular diagnostics using biomarkers are already yielding positive results.
An example is the experiment of Chinese scientists. In 2018, the world's first twins were born with a modified genome in China. Using gene editing, scientists have created protection against the human immunodeficiency virus. Children are completely healthy and not predisposed to the development of this disease, they’re still being observed. The task of the experiment is to strengthen the health of the twins and get closer to increasing the health of all mankind.
Scientists are actively exploring anti-aging methods. Now they identify the genes that control this process. Comparing the genome of young and old people using a computer, you can identify places with a greater amount of genetic damage. Researchers want to use their own cellular mechanisms to reverse the accumulation of errors in the mitochondria and thereby increase the cell life span.
The future of genomic medicine due to the computer revolution seems to be near. In just a few years, everyone will be able to acquire their own genomic map, which will indicate hidden diseases.
Recent genetic discoveries have shown that many ideas about the mechanisms of diseases were erroneous. Due to the accelerated development of technology, scientists will be able to see the genetic structure more clearly, and as a result, to treat and prevent diseases with greater accuracy, based on the individual characteristics of each patient. It’s coming soon!