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Eggs made from skin give hope to infertile couples

EGGS capable of being fertilised and making babies can be created in the laboratory from skin cells.

Scientists successfully produced three fertile baby mice using the technique, which involves transforming ordinary skin cells into personalised stem cells.

The same Japanese team created viable mouse sperm from embryonic stem cells earlier this year.

Together both advances greatly increase the likelihood of radical and controversial future treatments for restoring fertility.

It could mean creating sperm for men whose fertility has been wiped out by cancer therapy, or reversing the menopause in women after they have used up their natural supply of eggs.

However, many questions about safety and ethics will have to be answered first.


In August, scientists from Kyoto University in Japan announced that they had created sperm cells from mouse embryo stem cells. Injected into mouse eggs, the sperm produced embryos which developed into healthy baby mice.

The same team, led by Dr Katsuhiko Hayashi, carried out the latest research which focused on eggs rather than sperm.

The scientists mirrored their earlier achievement by transforming stem cells from mouse embryos into eggs which could be fertilised to produce offspring.

But they also took a further step by obtaining mouse pups from eggs derived from ordinary skin cells.

A genetic technique was used to turn the cells into induced pluripotent stem cells (iPSCs) which have the same properties as embryonic stem cells.

The cells were made to revert to the immature state they might have had while still part of an undeveloped embryo.

These were cultured with ovary cells in the laboratory before being transplanted into mouse ovaries where they matured into fully formed eggs.

After in-vitro fertilisation the resulting embryos were implanted into the wombs of female mice. Eventually three offspring were born that grew into fertile adults.

The researchers wrote in the latest online issue of the journal Science: "Our system serves as a robust foundation to investigate and further reconstitute female germline development in vitro (in the laboratory), not only in mice, but also in other mammals, including humans."