A human oocyteWIKIMEDIA COMMONS, RWJMS IVF LABORATORY
For more than half a century, textbooks have stated that women and other female mammals are born with all the eggs, or oocytes, they will ever have. This supply gradually shrinks with age, and ovaries are incapable of producing more of these reproductive cells.
This dogma has taken a pounding in recent years, however. Starting in 2004, Ji Wu of Shanghai Jiao Tong University in China and Jonathan Tilly of Massachusetts General Hospital isolated stem cells from the ovaries of mice, which could apparently divide to produce fresh oocytes. And earlier this year, Tilly announced that he has found cells with the same qualities, known as oogonial stem cells (OSCs), in the ovaries of middle-aged women.
These discoveries promised to offer new treatments for fertility, ...
