Андрей Николаевич Фоменко - The Power Of Youth. How To Tune Our Mind And Body For A Long And Healthy Life стр 5.

The first and simplest assumption of how certain traits are inherited was that the traits of both parents are "mixed" in the children, so the children are something between the mother and the father. However, already ancient Romans knew that this process had to take place differently.

In the mid-nineteenth century, the experiments of the Austrian friar Gregor Mendel made us closer to the modern understanding of the memory of generations. The examples from his observations of plants showed that traits are not mixed, but are transmitted in the form of discrete (isolated) units to the next generations. The scientific community did not attach great importance to his discovery.

Only in 1900 did botanists Hugo de Vries, Carl Erich Correns, and Erich Tschermak obtain similar to Mendel's results and, one after another, published studies that confirmed his hypothesis. In 1909, Danish biologist Wilhelm Johannsen called the discrete units responsible for the transmission of traits "genes", and in 1910 American geneticist Thomas Hunt Morgan established that genes are located in chromosomes. Scientists were able to explore the function of chromosomes only in the middle of the twentieth century when it turned out that hereditary information is contained in DNA.

Less than 70 years have passed since James Watson, Francis Crick, and Rosalind Franklin deciphered the structure of DNA. Since then, many discoveries have been made on the structure of the human body and using this information to prolong life. And for that, we must take a closer look at what DNA is.

OUR GENETIC CODE

Deoxyribonucleic acid (DNA), which is found inside the nucleus of every cell, holds the information that makes an organism what it is. To understand what it looks like, you can imagine a zipper twisted into a spiral. This long spiral chain, consisting of two strands, is constructed of four blocks called nucleotides: adenine  A, cytosine  C, guanine  G, and thymine  T. The entire DNA "text" consists of about six billion "letters" and contains "instructions" for the construction of every cell in our body. Each of the nucleotides has a pair from another strand, to which it is joined by hydrogen bonds. Adenine will always be paired with thymine and cytosine with guanine.

Regions of nucleotide sequences are called genes. The set of genes received at birth is the genotype, and all hereditary material contained in a cell is called a genome.

Proteins are the levers by which DNA controls the body. They are necessary for various biochemical reactions (as catalysts), metabolism, digestion, wound healing, etc.  for all the complex physiological interaction that ensures the health and life of the body. Proteins are formed during gene expression, the conversion of the hereditary information located in genes.

Expression occurs in several stages, but the key ones are transcription and translation. When the cell needs a certain protein  the transcription starts, i.e., the sequence of nucleotides in the right part of the DNA is copied into the ribonucleic acid (RNA). These RNA copies of DNA fragments act as matrices for protein synthesis  the translation starts.

The information flow in cells is directed from DNA to RNA, from RNA to protein  this is the central dogma of molecular biology.

The global Human Genome Project, completed in 2003, found that there are about 22,000 genes encoding proteins in human cells. Quite interesting, because before it was supposed to be at least 100 thousand. But it turned out that humans do not need so many genes, because each of them can perform several functions at once and synthesize several protein variants.

Except for the coding DNA, there is also non-coding DNA in the cell  the one that does not synthesize proteins. It makes up about 98 % of all human DNA. It is often called "junk DNA," because it is not yet fully understood exactly what functional activity non-coding DNA has. However, despite its name, it is also important for the life of the organism, and part of it plays a role in epigenetic (remember this word) regulation.

It can be said that genes are essentially eternal. Each of the DNA molecules can control its reproduction: copy itself and continue to exist for millions of years. But genes can change  various conditions affect them  and human health depends on these changes (mutations) because they are the root cause of many diseases.

GENETICS AND MEDICINE

Human genes are like little computer programs, embedded in humans since ancient times. For example, tens of thousands of years ago the insulin receptor gene in adipose tissue made sense for our ancestors: it helped to store as many calories as possible at a time when food was always in short supply. Today, however, humans have no need to forget hunger, so the gene does more harm than good: problems such as overweight and obesity develop at double speed. The modern computer age requires humans to update their genetic code, and scientists already can modify it.

Many see the possibility of defeating many serious diseases, including cancer, in genetics. Today, there are promising gene therapies against cancer  they allow us to edit DNA information. This enables specialists to "remove" harmful genes and activate useful ones.

Chimeras are animals or plants whose cells contain genetically distinct material. According to scientists, the creation of such organisms will help solve the transplantation issue, because human organs can be grown in them.

In 2014, scientists at the Massachusetts Institute of Technology discovered one of the mechanisms of genome editing, CRISPR/Cas9. This technology allows cutting double-stranded DNA anywhere, while other methods have their limitations and are more difficult to perform. With this method, it has become possible to perform faster and more precise modification of DNA in the genome, as well as to introduce more than one gene into a modifiable organism at a time. This method is cheaper and simpler than previous developments. Not surprisingly, CRISPR/Cas9 has been used more in recent years and is finding new applications.

Specialists are developing customized programs to significantly improve overall health: techniques such as genome analysis, gene therapy, and molecular diagnostics using biomarkers are already yielding positive results in animal experiments. And in 2021, the first human study of Alzheimer's disease gene therapy was launched: researchers from the University of California, San Diego injected patients with a harmless virus that can activate a gene associated with slowing and preventing the process of neurodegeneration.

On average, termites live from two months to two years when it comes to workers and soldiers, but their queens live ten times longer (from 25 to 50 years). If termites lived as long as humans, monarchs would reach the age of 1,000 years.