Process to transform embryonic stem cells into fertile eggs

Researchers at Monash University have developed a process that causes embryonic stem (ES) cells to develop into ovarian structures containing eggs. Dr Orly Lacham-Kaplan from the Monash immunology and stem cell laboratories has presented their findings at the annual meeting of the European Society for Human Reproduction and Embryology.

This provides hope for sterile women who in the future might be able to obtain eggs that contain their own genetic material through this process.

In 2003, international scientists demonstrated that ES cells could spontaneously develop into structures containing eggs while still maintained in a culture containing foetal calf serum. However the result has not been able to be replicated then.

In response, Dr Lacham-Kaplan has developed a simple, repeatable system to support the development of ES cells into ovarian structures containing egg, even though the system has involved only mouse ES cells at this stage.

"The eggs obtained from the process are at an early stage of development. Further studies are required to explore whether they're normal and able to mature and participate in fertilisation and embryo development," said Dr Lacham-Kaplan.

Dr Lacham-Kaplan's ultimate goal is to find ways for infertile couples to have children. "Some people just don't have eggs or sperm and there's little we can do for them except use donor material. The ability to develop eggs in vitro could primarily assist sterile women but could also reduce the ongoing strain on donor egg programs."

It could also help create a "bank' of eggs that could be used for nuclear transfer " where an egg's genetic material is removed and replaced with that of a sterile woman.

"Once the embryoid bodies were in an environment with growth factors sufficient for differentiation and they were not exposed to the factors responsible for the differentiation into male reproductive cells, they spontaneously differentiated into female reproductive cells even though they were originated from male ES cells."