From Dolly to a human copy
The inevitable Clone Attack
Valery Spiridonov, the first candidate for a body transplant, talks about how modern technologies for cloning living organisms were born, and discusses the consequences of their appearance for humanity.
The Key of Life
The beginning of research on alternative bio-reproduction dates back to 1885, when the German scientist Hans Driesch began to study reproduction methods by experimenting on sea urchins and other animals with large eggs. In 1902, he managed to raise two full-fledged sea urchins, dividing one embryo into two halves at the first stages of its growth.
A fundamentally new cloning method was developed in the 1940s by the Soviet embryologist Georgy Lapshov. He isolated the nucleus of a non-reproductive cell and injected it into an egg with a previously extracted nucleus. This cloning method is called "kernel transfer".
Similar experiments were later carried out by American embryologists with frog tadpoles. And in 1996, the news about the successful cloning of Dolly the sheep spread all over the world. It was the first mammal cloned from adult cells.
Later, scientists tried to clone many more animals: mice, pigs, goats, cows, horses, rats and others. At the same time, new methods of genetic engineering were created that allow changing the DNA of an embryo during cloning and performing other fantastic things that are commonplace for science and medicine today.
However, the purpose of such experiments was not only to recreate a population of rare animal species, but also to test cloning technologies and methods to create a copy of a person or his individual tissues.
Copies are illegal. Legislative regulation in Russia and the world
In most countries of the world, a temporary ban has been imposed on cloning. It is primarily due to ethical issues, as well as the imperfection of existing technologies. When scientists carry out the cloning process, they simultaneously create hundreds of embryos, most of which do not survive to the implantation stage.
In addition, observations of the length of telomeres, the end sections of DNA, show that clones should have a shorter lifespan than their "parents", which, however, is not yet evident during observations of real-life clones, despite shorter telomeres than in animals of a similar age conceived naturally.
In Russia, since April 19, 2002, the federal law "On a temporary ban on human cloning" has been in force. This document expired in 2007. Then the moratorium was extended in 2010 for an indefinite period until the entry into force of the law establishing the procedure for the use of technologies in this area. At the same time, the law does not prohibit the cloning of cells for research purposes or for transplantation.
Despite the resistance of politicians and the public, the first laboratory studies and experiments on human embryos were recently conducted in China, the USA, the UK and the Netherlands. In other countries of the world (for example, in France, Germany and Japan), such experiments are still beyond the law.
If we consider this issue from the point of view of religion, then we can say that any kind of cloning is unacceptable for representatives of almost all faiths of the world.
At the moment, there is no reliable information about the experiments conducted on human cloning. The US National Human Genome Institute, one of the main research centers working in this direction, identifies three types of cloning: genetic, reproductive and therapeutic.
Gene cloning
Cloning of genes or DNA segments, according to the definition of the University of Nebraska, is a process in which DNA is extracted from cells, cut into parts, and then one of these parts containing one or another gene is inserted into the genome of another organism.
As a rule, its role is played by various microbes, whose DNA is much easier to manipulate than the genome of a human or other multicellular living beings, whose genetic material is packed inside a nucleus isolated from the rest of the cell.
Having received several hundred such microbes with "cloned" foreign DNA, scientists observe how their vital activity has changed, and select those bacteria that contain interesting genes that can, for example, make plants invulnerable to attacks by various pathogenic fungi or protect them from pest attacks.
Similarly, the "cloning" of human genes in the DNA of microbes allows molecular biologists to look for the causes of various genetic diseases and create gene therapies that can fight them.
Therapeutic cloning
Embryonic stem cells and their analogues, made from "reprogrammed" skin cells or connective tissue, can turn into almost any type of cells in the body. This feature allows them to recreate tissues and organs compatible with the recipient's immune system.
In Russia, this process is called cellular reproduction. It is similar to reproductive cloning, but the growth time of the culture in this case is limited to two weeks. After 14 days, their reproduction process is interrupted, and the cells are used in laboratory conditions. For example, to replace the affected tissues. They can also serve for testing therapeutic drugs.
Artificial skin is already grown in the UK by this method, and in the USA they create full-fledged bladders.
Reproductive cloning
Cloning in the future could completely solve the problem of infertility – the famous Dolly lamb was a vivid example of this.
The source of the genetic material was the cells of a deceased sheep, another sheep became the egg donor, and the third animal played the role of a surrogate mother. Of the 277 cells, only 29 developed to the state of an embryo, only one of which survived.
Despite the uniqueness of the experiment and the scientific breakthrough for that time, its results were criticized.
The main reason is that the experiment was not clean from the point of view of genetics. In addition to nuclear DNA, part of the genome is contained inside the so-called mitochondria, cellular "power stations". In this case, Dolly inherited mitochondria not from her "genetic" mother, but from an egg donor, which is why she cannot be called an absolute clone. The question arises – is it possible in principle to create an ideal copy of any person or animal?
There are no absolute clones?
Even if the clone is initially genetically identical to the original, its similarity to it will inevitably decrease over time. This will affect both external and internal characteristics.
In particular, new random mutations constantly arise in the genome of humans and animals, so that the clone and the original will become dissimilar already in the first seconds of their "separate" existence. Even natural "clones", identical twins, initially have several dozen different mutations, and their number gradually increases after their birth.
Moreover, if we recall physics, we will notice that the very laws of quantum mechanics prohibit the existence of perfect copies of any objects.
An uncertain future
Nevertheless, science does not stand still, and over the past decades, cloning techniques for both genes and organisms have become much safer and more reliable, which reduces the likelihood of unsuccessful cloning or errors during DNA transplantation into an alien organism.
For example, the emergence of cell "reprogramming" techniques allows scientists today to obtain large amounts of stem cells and even grow full-fledged embryos without sacrificing other embryos for this. So far, such cells are used only in laboratories, but in the future they may find their place in the treatment of Parkinson's disease, Alzheimer's, the consequences of strokes, blindness and many other health problems.
The improvement of biotechnologies and the accumulation of scientific knowledge in the field of genetic engineering opens up new opportunities for humans. Elimination of genetic diseases, biocompatible transplantology, alternative solutions to infertility problems and, possibly, the birth of children with specified parameters.
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