http://www.guardian.co.uk/uk_news/st...510299,00.html
Scientists have raised the possibility that fertilised human embryos
might be created in a laboratory dish from artificial sperm and eggs
before being implanted in the womb. Sheffield University researchers
took a step towards developing the vital ingredients for human
reproduction from embryonic stem cells, sparking ethical questions of
how far experts should go in developing artificial reproduction.
The consequences of such work might even mean gay couples or single
men could produce children while women's fertility would no longer be
ended by the menopause. It is a far cry from present artificial
fertility techniques, where embryos are made in the lab from human
eggs and sperm collected from donors.
Although the successful mimicking of biological functions still might
be some way off, it joins other research, including a project on an
"artificial womb", in raising profound issues about the nature of
human life and parenthood.
A researcher from the Sheffield team will today tell the annual
conference of the European Society of Human Reproduction and
Embryology in Copenhagen that human embryonic stem cells might be
developed in the lab into early forms of cells that become eggs and
sperm. They hope their work could remedy severe shortages of donated
human eggs and sperm, and improve assisted reproduction, for
instance, by implanting synthetic cells in men to correct fertility
problems.
Behrouz Aflatoonian, a PhD student at Sheffield, said studies with
embryonic, or master, cells from mice had shown them capable of
developing into a further stage, primordial germ cells, and
subsequently eggs and sperm. Cells from embryos donated by couples
undergoing fertility treatment were used to see if the same was true
in humans.
"The human embryonic stem cells were allowed to develop into
collections of cells called embryoid bodies. The embryoid bodies were
tested to see which genes were active, or 'expressed', in them and it
was found that within two weeks a very tiny proportion of cells in
the embryoid bodies began to express some of the genes that are found
in human primordial germ cells."
Mr Aflatoonian added: "Embryoid bodies can differentiate into all
sorts of tissue, so we need to choose the cells that are going to
develop into primordial germ cells and then work out how far we can
encourage them to grow into gametes [sperm or eggs].
"Producing functional gametes is far more difficult, because we have
to recreate for the cultured cells the environment of the developing
follicle for egg development or the tissue of the testis for sperm.
We want to test whether the human embryonic stem cells can
differentiate to cells that produce the hormones for sperm and egg
development and isolate these as well."
Professor Harry Moore, head of the Sheffield laboratory, said the
work would enable scientists to study the earliest processes of how
the ovary and testis developed.
"Many scientists believe that environmental chemical pollutants that
mimic the action of hormones might interfere with human development
at this stage and cause congenital abnormalities, infertility and
possibly cancer, in particular testicular cancer."
Anna Smajdor, a researcher in medical ethics at Imperial College,
London, said that in the future, "this technology would offer an
obvious solution to infertile couples".
"Gay couples could have children genetically related to both. Single
men could even produce a child using their own sperm and an
engineered egg, opening the way to a new form of cloning. Women's
fertility would no longer need to be curtailed at the menopause.
"These possibilities raise new questions about how we define
parenthood and about how we decide who has access to these new
technologies."
wow...gonna be some ugly court cases...
Tetris Champion!
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