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Ovary stem cells can produce new eggs: study

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A new study by researchers from Harvard says that ovaries may be capable of producing new eggs, a discovery which, if true, overturns the long-held belief within the scientific community that a woman is born with a limited number of eggs.

"Our current views of ovarian aging are incomplete. There's much more to the story than simply the trickling away of a fixed pool of eggs," the study's lead researcher, Jonathan Tilly of Harvard's Massachusetts General Hospital, told Time magazine.

Special stem cells in ovaries are capable of generating new eggs, according to the study, published in the journal Nature Medicine.

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"We've isolated, essentially, the female equivalent of the stem cells that we know exist in men that actively make new sperm. So having these cells now isolated, I think, opens up a lot of opportunities to consider that we simply couldn't fathom before," Dr. Tilly told Voice of America.

Indeed, fertility experts such as Allan Pacey from the University of Sheffield have said the study's findings "re-write the rule book." Dr. Pacey told the BBC that the study "opens up a number of exciting possibilities for preserving the fertility of women undergoing treatment for cancer, or just maybe for women who are suffering infertility by extracting these cells and making her new eggs in the lab."

In the study, researchers isolated the rare cells from ovaries and placed them in culture outside the body. Over a period of several months, those 100 or so cells were made in to hundreds of thousands of such cells and, as Dr. Tilly told Voice of America, "We noticed that these cells would spontaneously generate immature eggs, all on their own, in these cultures."

While the study's findings, if true, are a major change in our understanding of human fertility, independent experts have cautioned that the cells are "some way" from any potential clinical use.

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