Biology teachers have always taught that a woman is born with her lifetime supply of eggs. That means that she cannot ever generate more, for example, the way men constantly produce sperm.
As a result, woman’s eggs are constantly exposed to environmental factors that can permanently damage the DNA or eggs. Therefore, women receiving cancer treatments that destroy their eggs will have no way to reproduce with their own eggs unless they have the foresight to have them cryopreserved.
However, new research out of Harvard Medical School suggest that a woman’s ovaries may contain mitotically active stem cells that can generate mature eggs.
By fluorescently labelling only the actively dividing cells in the ovaries, researchers were able to isolate the dividing cells using a fluorescence-activated cell sorter. The cells were then placed in culture and found to grow and divide normally for months.
The researchers took the experiments a step further and found that by injecting these human stem cells into the ovaries of adult mice, they could generate mature eggs.
This report is exciting for the field of reproductive medicine, as it provides hope for a future where medical technology will be capable of generating mature, chromosomally normal eggs for women who cannot conceive.