"Scientists announced that they had restored movement to
paralysed mice by injecting stem cells into their spinal fluid"
Feb 2004: " Korean
Scientists claim to have cloned 30 human embryo's"
Aug 2004: "
British scientists get ok to clone human embryos"
Interview about stem cell therapy
Other Interesting Cloning Viewpoints
South Korean scientists have created 30 human embryo clones.
This is the potential significance of the announcement:
What have the Seoul researchers done? Professor Woo
Suk Hwang and colleagues created embryos that were the exact
genetic copies of the women who donated the eggs and cells to
make them. They produced 30 embryo clones that divided over
several days to a stage where special cells known as embryonic
stem cells could be extracted.
How credible is the research?
Several groups have made claims in the past for similar
work. In some cases, no evidence was presented to back up the
assertions. In others, where supporting data was published, the
embryos stopped dividing at a very early stage. The Koreans, on
the other hand, have shown their embryos to be long lasting.
What is more, they have subjected their work to independent
scrutiny and a paper detailing their experiments has been
published by the international journal Science.
What made the Koreans successful?
The researchers have a proven track record in animal
cloning. Indeed, one of the critical steps credited with making
these embryos was developed in the field of cattle cloning. The
South Korean team also credits its success to the use of
extremely fresh donor eggs, and a special method for emptying
the eggs prior to injecting them with the genetic material to be
copied. That genetic material came from the nuclei of cumulus
cells. These are tiny clouds of support cells that surround and
nourish a developing egg in a woman's ovaries. Cumulus cells
were used to produce the world's first cloned mouse in 1998.
What is the point of the research?
The Koreans extracted embryonic stem cells from their
embryos - "master" cells that can divide into virtually any of
the body's tissues. The team demonstrated the beginnings
of this differentiation and saw it progress still further when
the cells were transplanted into mice.
The eventual aim is to use such cells to replace those that have
failed in patients with degenerative diseases, such as some
heart conditions and Parkinson's, or in spinal cord injuries.
This is known as therapeutic cloning. The Korean researchers see
it as very different from reproductive cloning - attempting to
bring about the birth of a cloned baby.
How far away is therapeutic cloning?
Experts believe it will be many years before stem
cell treatments based on cloning technology are available. If
the cells come from a cloned embryo they should not be rejected
by the patient because they match exactly that individual's
genetic make-up. At the moment, patients have to take powerful
drugs to prevent their body's immune system from attacking
tissues transplanted from another person.
Are there not ethical concerns here?
All embryo research draws the criticism that it is
tampering with cells which have the potential to be human
beings. The Korean experiments were given approval by an ethical
review board and all the women who donated cells and eggs gave
informed consent - but this will mean nothing to those who are
uncomfortable with this kind of science.
Could this latest work bring a cloned
baby closer? Potentially, yes. Scientists have been
struggling to clone monkeys. It is clear there are particular
difficulties involved in making genetic copies of primates. The
Korean research shows some of these technical hurdles can be
overcome and those minded to produce cloned babies will attempt
to use the new information to make children.