Human cloning: difficulties and prospects

How close are we to the first successful human cloning?

Ilya Khel, hi-news.ru , based on the materials of the Futurism website: Abby Norman, How Close Are We to Successfully Cloning the First Human?

Cloning people has become an extremely popular science fiction plot, and we have already despaired of waiting for it to step off the pages and screens into real life. However, in fact, we can be much closer to this than the usual fantastic heroes. At least from the point of view of science. The obstacles that stand between us may have less to do with the process and more to do with its potential consequences and ethical warfare. Although science has come a long way in this direction in the last century, when it came to cloning a menagerie of animals, humans and primates, there were always insurmountable obstacles. We have already learned how to clone human cells. What's next?

The surprisingly complex concept of cloning boils down to a fairly simple (in theory, at least) practice: you need to take two cells of the same animal – one of them will be the egg from which you removed the DNA. You take DNA from another somatic cell and put it inside a DNA-deprived cell. Any offspring of this cell will be genetically identical to the parent cell. While in humans reproduction is the result of combining two cells (one from each parent, each with its own DNA), the method of cellular photocopy does take place in nature. Bacteria reproduce in the process of double division: each time a bacterium divides, its DNA also divides, so each new bacterium is genetically identical to its predecessor. Unless some mutations occur in the process – and even then they can be a survival mechanism by design and function. Such mutations allow bacteria, for example, to develop resistance to antibiotics that try to destroy them. On the other hand, some mutations are fatal to the organism or do not allow it to be born at all. And although it may seem that the choice inherent in cloning can bypass these potential genetic disadvantages, scientists have found that it is not necessary.

What do the experts say?

Although Dolly the sheep is considered the most famous animal that has ever been cloned with the help of science, she is obviously not the only one of her kind: scientists have cloned mice, cats and several types of cattle in addition to sheep. Cloning cows in recent years has provided scientists with an understanding of why they are not doing everything: starting with problems with implantation and ending with the aforementioned mutations that lead to the death of offspring. Harris Levin, a professor in the Department of Evolution and Ecology at the University of California, Davis, and his colleagues published a paper on the effects of cloning on gene expression in the journal Proceedings of the National Academy of Sciences back in 2016. In a press release of the study, Levin noted that the results proved invaluable for improving animal cloning techniques, but their discoveries "also highlighted the need for a strict ban on human cloning for any purpose."

Creating whole mammals using reproductive cloning has proven to be a difficult process both practically and ethically, says Stanford University lawyer and ethicist Hank Greeley:

"I think no one understood how difficult it would be to clone some species and easy to clone others. Cats are easy, dogs are difficult, mice are easy, rats are difficult, humans and other primates are very difficult."

Cloning human cells may, on the contrary, be much more applicable to humans. Scientists call this process "therapeutic" cloning, that is, cloning for therapeutic, therapeutic purposes, and distinguish it from traditional cloning, which has a reproductive background. In 2014, scientists created human stem cells using the same cloning technique with which they created Dolly the sheep. Since stem cells can be made to become any cells of the body, they will be extremely useful in the treatment of diseases – especially genetic diseases or when a patient needs a transplant of another organ, the donor of which is often unavailable. This potential application is on the way: earlier this year, a Japanese woman suffering from age-related macular degeneration was treated with induced pluripotent stem cells created from her own skin and transplanted onto her retina. Her eyesight has improved.

Most interested people agree that we are approaching the milestone of successful human cloning. 30% of respondents say that the first person will be cloned by 2020. What do you think?

Portal "Eternal youth" http://vechnayamolodost.ru  26.06.2017