Chinese scientists use mouse stem cells to grow new eggs

Scientists in China say by using stem cells from the ovaries of young and adult female mice they have been able to generate new eggs.

The research challenges the accepted idea in scientific circles that females of most mammalian species have lost the capacity for egg production at birth and could signify a step forward in addressing female infertility issues.

The existence of female germline stem cells (FGSCs) in postnatal mammalian ovaries is a controversial issue among reproductive biologists and stem cell researchers, current scientific opinion suggests that the production of eggs, known as oocytes, stops before birth for most species of mammals, including humans.

But scientists at the School of Life Science and Biotechnology at Shanghai Jiao Tong University, say they have discovered a way to generate new eggs using stem cells harvested from the ovaries of juvenile and adult female mice.

They believe their discovery may have important implications in regenerative and reproductive medicine but critics say while the results were interesting, independent confirmation was needed.

The scientific team led by Ji Wu say they isolated female germline stem cells (FGSC) from the ovaries of five-day-old and adult mice which were than cultured for more than six months and then transplanted into the ovaries of infertile female mice - apparently 80% of these mice then went on to produce offspring after natural mating.

The team say their results suggest that oocytes can be regenerated in sterile recipient females by transplantation of FGSCs - however experts are cautious and they say if the results can be independently confirmed it could advance understanding of ovarian stem cells and advance research on female infertility.

But they say more work needs to be done to understand what these new cells really are, and to verify the findings and the claims. The research is published in the journal Nature Cell Biology.