Mouse embryos cloned from unfertilised eggs*

By Kyoko Hasegawa in Tokyo

March 13, 2007 02:31pm
Article from: Agence France-Presse

JAPANESE scientists have succeeded in cloning mouse embryos from
unfertilised eggs, a breakthrough that could help resolve the passionate
ethical debate about stem cell research.

Advocates say research involving embryonic stem cells - cells that can
develop into various organs or nerves - can save lives by finding cures
for diseases such as cancer and diabetes.

But the research has provoked a furore among religious conservatives,
who argue that it destroys a human life - albeit one at its earliest
stage of development.

President George W. Bush has banned all federal funding for stem cell
studies in the United States, the world's biggest research hub.

One proposed alternative has been to use unfertilised human eggs, but
this presents the major obstacle of trying to persuade healthy women to
undergo the painful process of donating eggs.

A Japanese team said it has found a potential future solution - it
performed in vitro fertilisation with mice and found that egg cells that
failed to be fertilised could be used to make cloned embryonic stem cells.

The process could be put to use among human eggs that would have gone to
waste during in vitro fertilisation.

"If we can use egg cells that would have been dumped, then the problem
of finding donors will be solved,'' said Teruhiko Wakayama, who led the
study at the Japanese government-backed Riken research foundation.

"Before our findings, it was believed that only fresh eggs could be
used. But if incompetent eggs can be cloned, then scientists could be
given eggs that failed to be fertilised and would have been abandoned in
fertility clinics,'' Mr Wakayama said.

The study appeared in the February 20 issue of US scientific journal
Current Biology.

Experts believe the use of unfertilised, cloned eggs, if replicated in
humans, could ease ethical concerns, although it would be unlikely to
eradicate all opposition.

"Fertilised eggs in particular are regarded as the beginning of human
life in certain religions, namely Catholicism, so destroying them for
the sake of medicine can be controversial,'' said Ryuichi Ida, a
professor of international law and biology at Kyoto University in
western Japan.

"But if unfertilised eggs can be used without ethical problems such as
physically hurting donor women, that's probably less sinful than using
fertilised eggs,'' he said.