Cloning as a method of reproduction

How will clones change medicine?

Denis Rebrikov, Post-science 

Animal cloning and Ian Wilmut 

In order for a new person to appear, two types of gametes are needed: an egg and a sperm. After their fusion, a fertilized egg — a zygote - appears. It begins to divide and gives life to a new organism. This system was invented by evolution to combine different combinations of genetic information in the next generation, thus creating a variety of phenotypes. Charles Darwin formulated the principle of evolution absolutely precisely: we create diversity, and then we select the fittest. The selection is handled by nature itself, environmental conditions, and then the strongest survives, the one who was able to adapt. Selection is also made by man when he creates new agricultural varieties of plants and new breeds of animals and decides who needs to be propagated: we can influence which phenotypes are most adapted to us, and they remain.

Technologies of human work with genetic material and reproduction of mammals have led to the fact that we are able to reproduce an individual from a cell of an adult organism — this is called cloning an animal. Cloning a plant is already a simple thing: if you break off a leaf from a flower, which is then put in water or buried in the ground, then a new flower will grow. This does not surprise anyone anymore. But the fact that you can take cells from a sheep and grow a new sheep out of them made a splash. When Dr. Ian Wilmut performed such a procedure for a sheep in 1996 and published the corresponding work, ordinary people were shocked. But in the eyes of scientists, this was not a super breakthrough, because science was already moving towards this and there were certain technologies: by that time, from earlier stages of development, from the embryo, they were able to reproduce the organism. But Ian Wilmut was the first to grow a new organism from an already adult sheep.

Ian Wilmut and Dolly the sheep.

Is it possible to clone a person?

Wilmut's success provoked a kind of cloning boom in scientific experiments, every year articles were published on cloning a variety of animals. At the same time, it is much more difficult to clone a monkey than a human, because all technologies in the field of embryology have been worked out for us — today we use IVF (in vitro fertilization) as a routine medical procedure. We know how the embryo develops, what conditions and culture media are necessary for its development, how to collect oocytes, transfer the nucleus, and so on.

If a woman has a severe mitochondrial disease and mitochondria is transmitted through the maternal line, then all her children will have a hereditary mitochondrial disease. In such cases, the following procedure is used. The nucleus, which contains 99.9% of the genetic information, is taken from the egg and transferred to the nuclear-free egg of another woman, where healthy mitochondria are located. It turns out a kind of hybrid: nuclear information from one woman, and cytoplasm with mitochondria from another. The hybrid is fertilized with a sperm, and a child appears to whom genetic information was transmitted from mom and dad, and mitochondria — from a donor egg of a third person. This is a well-known procedure for a long time: the first such child was born 5-7 years ago.

Can we clone a human? Technically yes, and this brings us to the question, shouldn't this method of reproduction be made legal? Currently, human cloning is a legally prohibited reproduction technology. Why? After all, the safety of this procedure has been proven many times in experiments with animals. However, there is a hypothesis that cloning transfers all the mutations accumulated in the cell to a new organism, thereby increasing the risks of developing certain diseases in the next generation. It was shown in rats that it is possible to clone an organism, that is, clone a rat, grow a new organism, take a cell from it, from which to grow another rat by cloning. It turned out that by the 28th generation of clones, a certain genomic instability appeared, which already made it difficult to clone. 28 generations for mankind is 700-800 years. It is impossible to predict what will happen to humanity in 700-800 years if we start reproducing in this way.

Advantages of reproduction by cloning

Firstly, the problem of an unpredictable genetic result in the future is removed. Classical reproduction — reproduction by merging gametes — is a lottery: one genetic variant out of 70 trillion. Something amazing may turn out, or a sick organism may appear. And when we clone ourselves, we know what kind of genetics we are dealing with, and a big plus is if we have good genetics that can be edited a little genomically — to remove some flaws, to correct something - at the stage of the next iteration.

Secondly, the problem of sterility and infertility is removed: in order to reproduce by cloning, you need to have at least some cells, not necessarily gametes. Here, of course, the question of surrogacy arises, since an artificial uterus has not yet been created and we cannot tear this technology away from a person — in any case, a surrogate mother will carry the child. Then the question goes into the ethical sphere. Today surrogacy is a legalized procedure in Russia, and in some countries, for example in India, it is generally put on stream as a standard medical service. When we say that we choose surrogacy because a woman will not be able to bear a child, then this is one ethical aspect. And when we turn to him just because we want to, that's another matter. Although, for example, many couples from the United States buy surrogacy in India (it's inexpensive, about 10 thousand dollars), just so as not to burden a woman's body, since pregnancy causes her some damage.

And finally, thirdly, from the point of view of genetics, you get the same organism as yours, and, therefore, it could be a donor for you, for example, stem cells. The donation of stem cells is not a procedure that causes damage to a person. And with the consent of your "child", who is the same person as everyone else, you will be able to get younger stem cells. This technology could be a certain scheme for maintaining the life of the original organism, since its own cells, but much younger ones, will be transferred to it.

Thus, the technology of reproduction by cloning is the future of humanity. I hope that we will come to this in the near future.

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