Latest research by a Chinese team has challenged a long-held principle of reproductive biology, which says that female mammals are born with all their eggs and immature eggs either ripen and are ovulated or die off, until the supply is exhausted. The study is led by Kang Zou and Ji Wu of Shanghai Jiao Tong University and is published in the journal 'Nature Cell Biology'.

 

The Chinese researcher have claimed that the ovaries of adult and newborn mice seem to contain stem cells that can be grown into eggs that can be fertilized to create healthy offspring.  If it is true in case of human being, it could provide a source of eggs to extend female fertility, which declines as the ovaries’ supply is depleted with age and could raise the prospect of restoring female fertility and reversing the menopause.

 

The group isolated female germline stem cells (FGSCs) from the ovaries of five-day-old and adult mice. Then they grew these cells into a colony that kept dividing in culture. The scientists then killed off all the eggs in the ovaries of adult mice, and reseeded them with FGSCs that had been genetically modified to produce a green fluorescent protein.

 

The sterilized mice produced new eggs, which when fertilized gave rise to healthy babies that were themselves fertile. The green fluorescent protein was present in many of the babies, which suggests they came from eggs grown from the stem cells.