Cloning

The word cloning indicate the action to insulate an object, a being, and to multiply it with the identical one.

Thus, in , the word cloning indicates several things:

  • On the one hand, the fact of reproducing living organisms to obtain genetically identical beings; this can apply to the simple ones (cellular cloning, by taking away of only one cell, which is put in culture in an individual way) or with beings human, of animals, of plants (reproductive cloning). The whole of these cells, or individuals, form a single clone (as long as it is identical).
  • In addition, a technique of which consists in isolating a fragment from ADN and to multiply it with identical while "inserting it" in a "carrying" molecule of ADN called vector allowing its amplification. This technique of molecular biology perhaps used for a partial cloning, relating only to one fragment of genetic material (ADN), but also for the cloning of a whole gene allowing the production of recombining corresponding.

vector most commonly used being a molecule ofADN called .

By extension, the term of cloning is used in nonbiological fields, to indicate for any reproduction with the identical one.

Synopsis

Natural cloning

In nature, the cloning is nothing more than one mode of reproduction among all those at the disposal of the alive beings. It is even most widespread since it relates to all the cells procaryotes (division), almost all them eucaryotes unicellular (mitosis) except for those which practise the sexuée reproduction (méïose), but also of many plants and animals pluricellular. Thus, certain animals cut into two can give two genetically identical individuals as it is the case at hydres. Moreover, the cells of the complex organizations generally reproduce by cloning.

The cloning is scientifically obtaining a being living genetically identical to the relative who gives him birth. It is thus opposed to sexuée reproduction who requires two parents. One should not however not confuse the cloning with certain forms of reproduction assexuées such as parthenogenesis or we have generation of gamètes, therefore meiosis. The children are not identical to their parents.

One often assimilates the birth of twins monozygotes at higher animals and atman with a form of natural cloning. It is not however the case. The two children are certainly identical between them (technically the children form a clone) but not to their parents and rise well from a sexuée reproduction...

Artificial cloning

Vegetable cloning

Technique of reproduction per cloning known under the name of " propagation by cutting "is largely used in horticulture (including by the gardeners amateurs) and associated other more professional techniques like the culture in vitro of méristèmes. In natural environment, that is observed with certain species emitting of the rejections, likeolive-tree (tree). When itortet initial ages, it emits rejections on the circumference of its stock. These ramets become then autonomous and separate between them at the time of disappearance of the initial stock with time.

Animal cloning

In the animal field, a step is crossed with XXE century thanks to the cloning starting from cores of differentiated cells reimplanted in ovocytes beforehand énucléés. This technique at the still low rate of success and which did not succeed that at some species is with its stammerings. Problems of accelerated ageing seem to be able to be connected to the state of télomères.

The year even where J.B.S. Haldane invent the word clone, the Chinese embryologist Tong Dizhou, with cloner an animal (a carp) is the first in , 33 years before ewe Dolly. It published its research in a Chinese scientific review which does not seem to be translated at the time. [ 1 ]

This technique allowed cloner the following species:

A second step is crossed before by the cloning of second generation (obtaining organization clonés starting from other clonés organizations) on mouse, then one .

Cloning human

Some researchers currently work on the reproductive human cloning. Without denying the technological exploit that such a realization would constitute, the international tendency seems to lean towards prohibition, for the moment, of research on the field. This being, one CNN survey show an interest always growing of the public for the technique. Arnold Schwarzenegger, governor of militated in favour of the human cloning (article). The opponents with the cloning seem all the more in a hurry to arrive at an international consensus. The United States, with more than fifty other countries, signed a call with a total prohibition of the human cloning. Another text prohibiting only the reproductive cloning was written by and supported by more than twenty country, of which , it , , and it . Research in favour of the reproductive human cloning still expresses a search fantasmatic, of the man, for sound immortality.

End , It movement raëlien, via , affirmed to have carried out the cloning of human beings but no scientific proof of their existence was brought.

It is allowed scientifically that the identity to be it is not summarized with sound genotype, which means that it is impossible to simply produce two identical beings by duplicating a genome. Moreover, the case of identical twin already informs us on what could be the reality of a "reproductive" cloning human: this reality is precisely not alarming (still that many cultures are wary of the twins, incarnation of one imitation dangerous) and would be a kind of invitation to science.

But all this raises questions ethics, , and important at this beginning of XXIE century leading to many debates.

This new form of generation presents for example legal difficulties concerning the legal statute of the clone. In particular when one speaks about "therapeutic" cloning, which implies that the clone is put at the service of others by its partial destruction, even total. From this point of view, certain put ethical questions can join those ofIVG.

In May 2005, of the researchers of and of announced the first clonings of human embryos at ends of therapeutic research.

Cloning and legislation

With UNO

8 March 2005, the general assembly of the United Nations decided to prohibit the cloning, even with the fine therapeutic ones. "Declaration of the United Nations on the cloning of the human beings", nonconstraining, was adopted with 84 votes for, 34 votes against and 37 abstentions. Among the countries which were opposed to this declaration find , it , , it, it , it and .

See the text of the declaration

In France

The French legislation on the cloning counts among most severe: thus, article 16-4 of Civil code proscribe any cloning, with goal eugenic, reproductive or therapeutic:

No one cannot attack the integrity of the mankind.

  • Very practical eugenic tending to the organization of the selection of the people is prohibited.
  • Any intervention having for goal is prohibited to give birth to a child genetically identical to another person alive or deceased.
  • Without damage of research tending to the prevention and the treatment of the genetic diseases, no transformation can be brought to the genetic characters with an aim of modifying the descent of the person.

In South Korea

In February 2004, South Korea is the first country in the world with cloner a human embryo for scientfic research.

In Great Britain

In , the Authority on the fertilization and the human embryology (HFEA) authorized professor Miodrag Stojkovic, of the university of Newcastle in England with cloner of the human embryos at therapeutic ends of research on the cell-stocks. Another authorization was granted in 2005 to professor Ian Wilmut of Roslin Institute ofEdinburgh. In May 2005, the teams of professors Alison Murdoch and Miodrag Stojkovic, based in Newcastle announced to have cloné a human embryo.

Internal bonds

External bonds


 

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