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- Details of the first human embryo to
be cloned have been released.
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- The watershed achievement in biotechnology
actually happened last November, but more information was revealed on Thursday.
It was achieved using a cell from a man's leg and a cow's egg.
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- The scientists who created the clone
see it as a significant step forward in the search for a way of producing
human stem cells.
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- These are "master" cells which
can develop into any type of cell - skin, bone, blood etc. They are believed
to have the potential to provide perfect-match tissue for transplantation
and the treatment of diseases such as Parkinson's and stroke.
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- Cloning questions
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- But this development will also see a
significant heightening of the debate over the ethics of human cloning
and, indeed, what it means to be a human.
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- American Cell Technology (ACT), a leading,
private biotechnology company, cloned the first human embryo and let it
develop for twelve days before destroying it. In a normal pregancy, an
embryo implants into the womb wall after 14 days.
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- Dr Robert Lanza, ACT's director of tissue
engineering, told the Daily Mail newspaper that the embryo cannot be seen
as a person before 14 days. The company say they have released news of
the discovery to try to allay fears over the artificial conception of life.
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- It is believed that many more human embryos
have been created and destroyed since November. Then it was announced that
stem cells had been cloned, not that embryos had been allowed to develop.
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- No cloned children
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- ACT say they have no intention of attempting
to use a cloned human embryo to start a pregnancy - their aim is "therapeutic
cloning" not "reproductive cloning".
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- Lord Robert Winston, a British fertility
expert, said the research was "totally ethical".
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- But opponents say that the development
of the technology makes the eventual birth of a human clone inevitable.
This, they say, would have profound implications for the nature of family
relationships, the law and health.
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- Tough technology
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- The technology used to create the clone
was very similar to that used to make Dolly the Sheep. Over 200 embryos
were used before Dolly finally appeared, showing that cloning is not a
well-understood or easy-to-perform technique.
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- It is understood that ACT used a cow's
egg. This had its DNA removed and replaced with human DNA. The new cell
was then chemically persuaded to behave like a new embryo and start dividing.
This is how ACT hope to cultivate stem cells.
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- But Dr Maisam Mitalipova, a pioneer of
this human-cow type of cloning, told the Daily Mail: "We didn't get
good quality embryos and so they may not get good quality stem cells."
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- Cloning competition
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- Another US company, Geron, are also reported
to be attempting to clone human embryos for therapeutic purposes.
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- They recently bought all the shares in
Roslin Bio-Med, a company set up to commercialise the cloning expertise
of the Roslin Institute, Scotland, where Dolly the sheep was created.
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- Geron has not publicly stated whether
their attempts have been successful and it may be that ACT have acheived
the feat first.
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