New hope for women who are infertile

Eggs are grown from skin cells

BABY animals are being created without eggs from a female. The eggs are grown from skin cells, fertilised in a laboratory and implanted in the mother.

The fertility breakthrough gives hope that the method could be used in humans to help infertile women have babies, but it also raises the prospect of babies being created using genes from two men, although such an embryo would still need to develop in a womb.

Japanese scientists developed the method using mice. Tissue cells from the tip of a mouse’s tail were reprogrammed as stem cells and turned into eggs, which were fertilised and implanted in female mice. They gave birth to 11 healthy pups, the scientists reveal in the journal Nature.

It is the first time stem cells have been used to create mature eggs outside a mouse’s body. If the process can be made to work for humans, it could offer hope to women who are infertile, for instance as a result of cancer treatment.

But Jacob Hanna, a stem cell biologist at the Weizmann Institute of Science in Rehovot in Israel, said the approach could also one day mean eggs are produced from a man’s skin cells – doing away with the need for a woman’s egg cells.

Hanna said such a method, giving a baby two biological fathers but no biological mother was “legitimate to explore when the right time comes”, Nature.com reported.

Such a prospect was years away, however, experts admit.

The researchers, led by Professor Katsuhiko Hayashi at Kyushu University, used cells from the tips of mouse tails to create pluripotent stem cells, which have the ability to transform into different tissues.

The stem cells were treated with a specific cocktail of chemicals and biological signals, including mingling them with gonadal somatic cells, taken from mouse embryos, which aid egg development. The r e s e a r c h e r s say although the somatic cells had to be taken from an embryo, they expect these, too, might be developed from skin cells. Once this is done, there would be no need for any embryonic tissue.

Although only 11 of 316 embryos created in the lab resulted in live births, British scientists working in the same field praised the achievement.

Martin Johnson, professor of reproductive sciences at Cambridge University, said the research was remarkable, while Professor Richard Anderson, of the University of Edinburgh, said: “This is the first report of anyone being able to develop fully mature and fertilisable eggs in a laboratory setting right through from the earliest stages of oocyte (egg) development.”

It’s legitimate to explore when the right time comes