id=”inContext_disabled”> 2013-05-16 12:00
id=”inContext_disabled”> [Photo: sxc / cc / ninci]
researchers have cloned human embryos by Dolly, which for the first time can be extracted stem cells – said the letter, Cell. “This opens up new possibilities for tissue and organ culture, but it also raises huge ethical controversy.
international team of scientists, led by Masahito Tachibana of the Oregon Health & Science University (USA), used ova donated to the experiment by one of the women. Removed from the nucleus, DNA containing the essential part, and instead introduced nucleus obtained from the skin of another adult person.
It is the oldest method of cloning from somatic cells, which was first used in 1996 to breed sheep Dolly.
Like the sheep embryo obtained, this time a man who began to share. The human embryo, however, the development was stopped after five days, when he was at the blastocyst stage, ready for implantation in the uterus. At this stage there are no longer stem cells, which result in all the tissues and organs of a new organism. However, you can use them for breeding the specialized cells in the laboratory.
anyone have not managed to do so. Although Hwang Woo-suk, South Korean scientist claimed to have received human stem cells from cloned embryos, but it quickly became apparent that his experiment was a fraud.
Other researchers obtained by Dolly human embryos, but they ceased to divide at a very early stage of development, when only 6-12 cell count.
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Dr. Dieter Egli of the New York Stem Cell Foundation Laboratory in New York cloned human embryo, which also led to the blastocyst stage. He did this, however, a different method. It is based on the fact that the nucleus of a skin cell is inserted directly into an egg donor still contains its own kernel.
cells with the dual core can be developed, but they contain a triple set of chromosomes (one single, part of the egg, and a double somatic cells). In this embodiment, contained in stem cells which are not suitable for tissue culture.
Dr. Shoukhrat Mitalipov of Oregon Health & Science University, said in a commentary on the research, the latest experiment is a huge step forward in stem cell trials and the use of their tissue culture. He admits, however, that you still need to conduct a lot of research to cloning and tissue engineering to be effective and safe.
Prof. Chris Mason University College London, in a statement for “bbcnews” compares the test to the first attempts of the Wright brothers, aviation pioneers who built the aircraft initially only able to raise the air and make short jumps. In his opinion, the same is now with the use of stem cells.
Other researchers pay attention to the moral concerns such experiments. Dr. David King of Human Genetics Alert warns that they are paving the way for human cloning. In his view, even publishing the results of such research is immoral. (PAP)
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