Magazine article Science News

Adult Women Might Replenish Eggs: Stem Cells Found in Ovaries Produce Precursors to Gametes

Magazine article Science News

Adult Women Might Replenish Eggs: Stem Cells Found in Ovaries Produce Precursors to Gametes

Article excerpt

A newly discovered type of stem cell in the ovary could mean big things for women's health, possibly leading to new fertility treatments and maybe even a way to delay menopause.

Since the 1950s it has been thought that women are born with all of the egg cells they will ever have. But with the discovery of egg-producing stem cells in mice and now in humans, it appears that the ovary can replenish its egg supply. Researchers led by Jonathan Tilly, a reproductive biologist at Massachusetts General Hospital in Boston, report the finding online February 26 in Nature Medicine.

Others hail the work as a genuine breakthrough with huge implications. "This is like discovering a new planet in our solar system that has a bacterium on it," says Kutluk Oktay, a reproductive biologist at the New York Medical College in Valhalla. At the very least, he says, the cells offer hope for extending a woman's reproductive life span.

Tilly didn't set out to overturn the dogma that women don't make new eggs. Studying the onset of menopause, he and his colleagues developed ways to track the death of egg cells over time. When counting the number of healthy egg cells in mouse ovaries, the researchers saw a steady decline with age as expected. But the team also found that dying cells greatly outnumber the starting population of eggs. "What we had was a math problem," Tilly says. "We refocused all of our efforts on this glaring mathematical dilemma."

In 2004, Tilly's group reported the answer to the math problem: There are more dying eggs than healthy ones because stem cells in mouse ovaries are constantly making more eggs, which then die off. The discovery didn't go over well. "The vast majority of our colleagues were not very receptive," Tilly says. Many of those who did accept the existence of egg-forming stem cells in mice didn't think humans would have similar cells. …

Search by... Author
Show... All Results Primary Sources Peer-reviewed

Oops!

An unknown error has occurred. Please click the button below to reload the page. If the problem persists, please try again in a little while.