Questions and Answers
Where will arrive with human cloning?
The goal of researchers is to create cells to repair diseased tissues, but the technique poses ethical
Into Human Cloning
A group of American researchers Oregon has just proposed, the journal Cell, a new cloning technique.
1 How does it differ from that used for Dolly in 1996?
The two techniques are a little ‘different. To create Dolly the researchers ‘molten’ a cell of the mammary gland, with all its genetic heritage, with an oocyte lacking, however, the nucleus: the result was a sheep “photocopy” of the donor udder cell.
In Oregon used the method of nuclear transfer: they took the nucleus of a cell of an individual’s skin and have it transplanted into an egg cell stripped of its DNA. This has given rise to embryonic stem cells with the same genetic characteristics as those of the individual starting. This is the same method that had already used John Gurdon on frogs in 1962.
2 What is new in the American method?
The novelty proposed by Shoukhrat Mitalipov, head of the team of researchers, is the use of the land where the cells are cultivated: in this case were used special factors, such as caffeine, capable of making the chromosomes more stable and increase the efficiency of the cells produced.
3 What is the purpose of these experiments?
is to produce pluripotent stem cells capable of differentiating into almost all types of cells in the , are used to repair tissue damaged by disease (stroke, Parkinson’s, spinal cord injuries, diabetes and so on). The advantage is that these stem cells can be taken from the same patient and have the same genetic characteristics: once transplanted, ie do not undergo a rejection by the body.
4 There are other ways to produce stem cells capable of giving rise to all the tissues of the body?
There is another method called “genetic reprogramming»: was developed by Shinya Yamanaka (Nobel along with Gordon in 2012). The Japanese researcher started from skin cells of adult mice and put them in the four core stem cell genes: genes that are able to rejuvenate and transform them into pluripotent stem cells.
5 You can get stem cells from other sources?
There is a third way, that most controversial from an ethical, which uses the same embryos to obtain cells totipotent. Apart from the ethical issues, these cells, when used to repair diseased tissues would suffer a rejection by the recipient organism.
6 In the past there has been talk of cloning false. What has happened?
In December 2002, Rael, leader of the Raelian sect (a movement that believes in extraterrestrials and immortality) had announced, together with the scientist Brigitte Boisselier, the cloning of a daughter, Eva. The newspapers around the world had talked about, but the story turned out to be, as expected, a hoax.
7 There are other cases?
Another “false” has fooled for a while ‘even the scientific community: the South Korean Hwang Woo-suk had published on Science , in 2004 and 2005, some cloning experiments: in some cases had used eggs from women and their nuclei taken from the same cells, in others had performed nuclear transfers in cells of patients. Eventually it was discovered that the data had been falsified, so the work has been withdrawn by the journal and the researcher has been convicted of fraud. The falsification, however, was not so much the experiments, which were succeeded, but the success rates that had been exaggerated by the researcher.
8 What is the difference between reproductive cloning and therapeutic cloning?
The first aims to produce stem cells for use in regenerative medicine: that is to repair organs and tissues damaged by disease. With reproductive cloning you will, however, make a copy of a living being. After Dolly were cloned, with the technique of nuclear transfer, many other species of animals, including rabbits, cows, and cats. According to some, the new method, proposed by researchers at Oregon might be so efficient as to make possible the cloning of monkeys. That man is, however, far away.
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