Dicen that the man is easier to clonar than an animal.

Scientists of the United States say now that a subtle genetic difference could cause that the clonación of human beings is easier to obtain in comparison with the practices that already have taken control of ewes, mice, cows and pigs. And they presented/displayed yesterday his tests in a magazine of his specialty. But other experts - who carry out clonaciones of different organisms already retrucaron to them that they were too simplistas.

The study was lead by the Keiths Killian and Randy Jirtle, of the University of Duke, who counted on the collaboration of specialists of the University School of Dublin, in Ireland, and of the Medicine Faculty of the University of Stanford, among others.

All of them maintain that the human beings could be - technically easier to clonar than the animals like the ewes. For example, the ewe Dolly, the animal clone obtained from another adult in 1996, obtained itself after 277 attempts. Or that the cows: in the INTA of the city of Balcarce this year were three preñeces of animals clones but no finished with the birth of a clone.

Considering the little efficiency of the technique at the present time, the investigators of Duke maintain that the humans - to just as others primates- has a genetic benefit that it prevents them with the excessive fetal growth, one of the problems that are accustomed to appear with the clonación animal.

The difference, according to affirms in the magazine Molecular Human Genetics, consists in which the humans and others primates count on two activated copies of a gene (called receiving of the factor of growth similar to the insulin type II). Each individual receives a functional copy of both ancestors. However, other animals as the ewes or the pigs receive only one activated copy of the gene by means of a strange process that the scientists still have not taken care to translate the Spanish and call ?imprinting?.

With the second deactivated copy of the gene, the animals are more prone to develop cancer and to undergo complications from the use of the clonación technique: the young is born greater than the normal ones, their lungs do not get to be developed totally and the immunity against certain diseases is reduced.

On the basis of studies which they did with genetic markers on different species (by all means that included the human one), the Killian scientist - a molecular evolucionista concluded: ?These are the first concrete genetic data that show that the clonación process would be less complicated in humans than in ewes?.

Killian affirmed that one of each three hundred embryos obtained by clonación pledges, and half with which pledges suffer of the syndrome of the great young, that can kill to the mother and he himself fetus. As the humans have two activated copies of the gene at issue, ?the excessive fetal growth would not happen if the humans were clonados?.

The point is that the complications by the clonación arise when the investigators manipulate the embryo in the laboratory. And thus they cause disturbances in the gene. For Jirtle, he is equal to when a program of a computer it does not work. No matter how hard the hardware is ready and in good conditions, the computer will not do what the user wants. That is to say, the group of Duke gives by seated who the differences between the amounts of copies activated of the gene can take to different outcomes when the clonación is used. But other experts accuse them to be too reduccionistas.

Ian Wilmut, the Scot who produced the Dolly ewe, said to him to the agency AP that is erroneous the interpretation of which the human clonación would be easier by that particular genetic advantage. According to Wilmut, that is against to clonar human with reproductive aims, the faults of the development of the placenta are very frequent in bovine clones. Perhaps this generates errors in the functions of other genes specifically implied in the development of the network of blood vessels of the placenta, noticed Wilmut.



?Simplista?

?He is simplista?, it thought the investigator in biotechnology animal of the Conicet and the UBA, Barañao Linen, with respect to the study of Duke. ?They suppose that the process of '' imprinting '' of a single gene is the only limitante factor in the clonación of mammals and it is not it?. The expert - who participates in a project of bovine clonación with an Argentine biotechnological company indicated that other genes exist that also the fetuses act in the mechanisms of regulation of the placenta and as large as. The veterinarian Jose Cibelli, the Argentinean who comprises of a American company that bovine clonación has made also emphasized in which to follow the action of a single gene ?is not sufficient?. And he commented to Bugler: ?The results are difficult to predict, and is a very high risk so that it practices in humans.

Consulted by Bugler by email, Gleen Mc Gee, prestigious investigator in bioética of the University of Pensilvania, in EE.UU., said that there are other dramatic problems produced by the clonación that the investigators of Duke did not consider. ?The lunáticos like (Panos biochemist) Zavos or Severino Antinori that they want to make clonación human cannot to prevent them?.

Source: www.clarin.com

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