Genetic Engineering FAQ

1. What is genetic engineering?

Genetic engineering is a modern direction of biotechnology, combining knowledge, techniques and techniques from a whole block of related sciences – genetics, biology, chemistry, virology, and so on – in order to obtain new hereditary properties of organisms.

The restructuring of genotypes occurs by making changes in DNA (a macromolecule that provides storage, transmission from generation to generation and the implementation of the genetic program for the development and functioning of living organisms) and RNA (one of the three main macromolecules contained in the cells of all living organisms).

If you introduce new genes into a plant, microorganism, animal organism or even a person, you can endow it with a new desirable characteristic, which it has never possessed before. For this purpose, genetic engineering is used today in many areas. For example, on its basis, a separate branch of the pharmaceutical industry was formed, which is one of the modern branches of biotechnology.

2. How did genetic engineering develop?

The foundations of classical genetics were laid in the middle of the 19th century thanks to the experiments of the Czech-Austrian biologist Gregor Mendel. The principles of the transfer of hereditary traits from parental organisms to their descendants discovered by him on the example of plants in 1865, unfortunately, did not receive due attention from contemporaries, and only in 1900 Hugo de Vries and other European scientists independently “rediscovered” the laws of heredity.

In parallel with this, there was a process of forming knowledge about DNA. So, in 1869, the Swiss biologist Friedrich Miescher discovered the existence of a macromolecule, and in 1910, the American biologist Thomas Hunt Morgan discovered, based on the inheritance of mutations in Drosophila, that genes are located linearly on chromosomes and form linkage groups. In 1953, an important discovery was made – the American John Watson and the Briton Francis Crick established the molecular structure of DNA.

By the end of the 1960s, genetics was actively developing, and viruses and plasmids became its important objects. Methods were developed for the isolation of highly purified preparations of intact DNA molecules, plasmids and viruses, and in the 1970s a number of enzymes were discovered that catalyze DNA transformation reactions.

Genetic engineering as a separate area of ​​research work originated in the United States in 1972, when at Stanford University scientists Paul Berg, Stanley Norman Cohen, Herbert Boyer and their research group introduced a new gene into the E. coli bacterium, that is, created the first recombinant DNA.

The PCR technique was first developed in the 1980s by the American biochemist Cary Mullis. The future Nobel laureate in chemistry (1993) discovered a specific enzyme – DNA polymerase, which is involved in DNA replication. This enzyme literally reads the lengths of the chain of nucleotides of the molecule and uses them as a template for the subsequent copying of genetic information.

In 1996, the first cloned mammal, Dolly the sheep, was born by transplanting the nucleus of a somatic cell into the cytoplasm of an egg. This event became revolutionary in the history of the development of genetic engineering, because for the first time it became possible to seriously talk about the creation of clones and the cultivation of living organisms based on molecules.

3. What are the technologies of genetic engineering?

In a short period of time, genetic engineering had a tremendous impact on the development of various molecular genetic methods and made it possible to significantly advance on the path of understanding the genetic apparatus.

This is how CRISPR technology appeared – a genome editing tool. In 2014, MIT Technology Review named it “the greatest biotech discovery of the century”. It is based on the defense system of bacteria, which produce special enzymes that allow them to defend themselves against viruses.

A unique discovery came in 2011 when biologists Jennifer Doudna and Emmanuelle Charpentier discovered that the Cas9 protein could be tricked. If you give him an artificial RNA, synthesized in the laboratory, he, having found a match in the “archive”, will attack it. Thus, with the help of this protein, you can cut the genome in the right place – and not just cut it, but also replace it with other genes.

In theory, CRISPR technology could edit any genetic mutation and heal the disease it causes. But the practical development of CRISPR as a therapy is still in its infancy, and much remains to be understood.

There are other genetic engineering methods, such as ZFN and TALEN.

  • ZFN cuts the DNA and inserts a previously prepared new fragment with the help of proteins with zinc ions (hence the name – Zinc Finger Nuclease).
  • TALEN does the same using TAL proteins. For both technologies, you have to create separate proteins, and this is a very long work, so so far these two methods have not found special application.

4. How is genetic engineering used in medicine?

Scientists to this day argue about the admissibility of eating foods containing GMOs (genetically modified organisms), and their use is largely justified. A large number of crops with altered DNA have been created, which makes it possible to give them greater resistance to diseases, pests and adverse conditions. There are at least 30 transgenic plant species permitted for production in at least one country. In our country, the use of such organisms is strictly regulated by the relevant legislation.

But genetic engineering methods are widely used not only in biology and agriculture, but also in medicine. Thus, in the treatment of a number of diseases, biological preparations are widely used – these are hormones, proteins, amino acids, vaccines, etc. Chemical synthesis of most of these substances is impossible, therefore genetic engineering comes to the rescue. The general principle for creating such drugs is as follows: a gene is inserted into the DNA of a microorganism (yeast, E. coli, etc.) or a cell culture, which is responsible for the production of the desired substance. The altered cell essentially turns into a small factory for the production of this compound. After thorough cleaning and processing, a preparation is obtained that can be used in medical practice. Insulins produced with the help of genetic engineering are becoming more and more widely used. In a similar way, a preparation of human growth hormone was obtained, which is extremely necessary for children with congenital pathology leading to short stature. In many sports, erythropoietin is used as a doping agent, it increases the body’s endurance due to a better supply of oxygen to tissues. And since the drug does not differ from that synthesized in the body itself, it is quite difficult to identify unscrupulous athletes.

A vaccine against the very dangerous hepatitis B is used all over the world – it is obtained from a genetically modified yeast culture. DNA vaccines are being developed that will help “create” immunity not only against infectious diseases, but also against a number of oncological, genetic, autoimmune diseases and other pathologies.

Genetic engineering methods have a huge future, recently it was reported that a boy suffering from a hereditary pathology leading to severe skin damage (epidermolysis bullosa) was transplanted with artificially grown genetically modified skin on 80% of the body surface.

5. How does genetic engineering affect human health and well-being?

Genome editing has had a significant impact on scientific research, agriculture, industry and medicine. Molecular biology research often includes transgenes – foreign genes – in bacteria and viruses to study gene function and expression. Bacteria were the first genetically engineered organisms. Scientists have unveiled the human insulin gene for the production of synthetic insulin, which is used by people with diabetes.

A technique called gene therapy allows a new gene to be introduced into a person so that the protein it encodes can be expressed in their cells. Gene therapy provides a cure or treatment for certain serious and otherwise incurable genetic diseases. Scientists have modified viruses to deliver new genes to host cells. These individualized viruses can infect diseased cells and insert the correct copy of the defective gene, treating human diseases such as severe combined immunodeficiency (SCID).

Although many gene therapy methods use modified viruses, the CRISPR / Cas9 system is becoming more and more popular. The CRISPR / Cas9 system shortens DNA by guiding – RNA sequences known as CRISPR – to direct molecular scissors – an enzyme called Cas9 – to specific regions of the genome. Scientists use this molecular tool to add, remove, or alter genetic material. CRISPR / Cas9 is used in mouse models to correct errors in genes that are responsible for Duchenne muscular dystrophy, hepatitis B, cataracts, and cardiovascular disease.

While genetic engineering can provide new treatments for diseases, it can also be used for other practical purposes. Transgenic goats have been developed that produce spider silk in their milk for industrial use. In agriculture, some plants have been genetically modified to improve characteristics such as nutrient content and pest resistance. Recent and future advances in genetic engineering are likely to continue to have an impact on both human health and well-being.

6. What are some ethical issues related to genetic engineering?

Genetic engineering has great potential, but where should we draw the line? Scientists and society must answer this question. Editing the human genome, especially in germ cells, is a major ethical issue. Most gene therapy modifies somatic cells, so genetic changes only affect humans. Changes in the human germ line, however, are also inherited by their offspring.

In 2018, a scientist shocked the world when he allegedly created the first children genetically modified using CRISPR. He tried to make twin girls resistant to HIV by introducing an unexplored germline mutation. His actions sparked outrage and concern as scientists and the public struggled with what this meant for humanity. It remains unclear how this will affect the health of girls, their future offspring or the population.

Another problem is the use of foreign genetic material to improve nutrition. Plants are the most abundant genetically modified food source, with 28 countries growing nearly 450 million acres of GM crops worldwide. While there is enormous potential to feed the world’s growing population, scientifically sound, long-term research is needed to address the concerns of critics of GMOs.