We have created human-animal embryos already, say British team
The Newcastle cybrids lived for three days and the largest grew to
contain 32 cells
Mark Henderson, Science Editor
April 2, 2008
Embryos containing human and animal material have been created in
Britain for the first time, a month before the House of Commons votes
on new laws to regulate the research.
A team at Newcastle University announced yesterday that it had
successfully generated "admixed embryos" by adding human DNA to empty
cow eggs in the first experiment of its kind in Britain.
The Commons is to debate the Human Fertilisation and Embryology Bill
next month. MPs have been promised a free vote on clauses in the
legislation that would permit admixed embryos. But their creation is
already allowed, subject to the granting of a licence from the Human
Fertilisation and Embryology Authority (HFEA).
The Newcastle group, led by Lyle Armstrong, was awarded one of the
first two licences in January. The other went to a team at King's
College London, led by Professor Stephen Minger. The new Bill will
formalise their legal status if it is passed by Parliament.
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Admixed embryos are widely supported by scientists and patient groups
as they provide an opportunity to produce powerful stem-cell models
for investigating diseases such as Parkinson's and diabetes, and for
developing new drugs.
Their creation, however, has been opposed by some religious groups,
particularly the Roman Catholic Church. Cardinal Keith O'Brien, the
head of the Catholic Church in Scotland, described the work last
month as "experiments of Frankenstein proportion".
The admixed embryos created by the Newcastle group are of a kind
known as cytoplasmic hybrids, or cybrids, which are made by placing
the nucleus from a human cell into an animal egg that has had its
nucleus removed. The genetic material in the resulting embryos is
99.9 per cent human.
The BBC reported that the Newcastle cybrids lived for three days, and
that the largest grew to contain 32 cells. The ultimate aim is to
grow these for six days, and then to extract embryonic stem cells for
use in research.
Once the technique has been tested, scientists hope to create cybrids
from the DNA of patients with genetic diseases. The resulting stem
cells could then be used as models of those diseases to provide
insights into their progress and to test new treatments.
It is already illegal to culture human-animal embryos for more than
14 days, or to implant them in the womb of a woman or animal, and
these prohibitions will remain in the new legislation.
Using cow eggs reflects a short supply of human eggs. There are also
ethical difficulties involved in collecting human eggs for research,
as the donation process carries a small risk to women.
Professor John Burn, a member of the Newcastle team, told the
BBC: "This is licensed work which has been carefully evaluated. This
is a process in a dish, and we are dealing with a clump of cells
which would never go on to develop. It's a laboratory process and
these embryos would never be implanted into anyone.
"We now have preliminary data which looks promising but this is very
much work in progress and the next step is to get the embryos to
survive to around six days, when we can hope-fully derive stem cells
from them."
The Newcastle team's decision to announce its success on television,
before its results have been published in a peer-reviewed journal,
will also trigger criticism from scientists.
Medical researchers said last night that the experiments were
important, but that they wanted to see published details before
passing judgment on their merits.
http://www.timesonl
ece
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StemCells subscribers may also be interested in these sites:
Children's Neurobiological Solutions
http://www.CNSfoundation.org/
Cord Blood Registry
http://www.CordBlood.com/at.cgi?a=150123
The CNS Healing Group
http://groups.yahoo.com/group/CNS_Healing
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