Making eggs from stem cells achieved in mice

A women’s eggs are laid down when she is a fetus and she is born with all of the eggs she will produce.  The number and quality decline as we age, which causes age-related infertility and finally the menopause. There is a huge debate about whether there is a special type of cell in the ovary that could potentially make new eggs but research is ongoing.

Scientists have tried to use stem cells to make ‘artificial eggs’ which could potentially increase a woman’s fertility.  Yesterday an important paper was published in Nature which shows that in the mouse, scientists from Japan have been able to take various types of stem cells and make functional eggs which resulted in live offspring.  They have been able to recreate the entire process of oogenesis (the making of an egg from a very immature cell to a fully mature egg) in a dish.

Eggs develop from special cells called primordial germ cells which have to undergo a complex maturation process to make a functional egg.  The same team had previously reported artifically making primordial germ cells and transferring these to a mouse ovary for maturation.  But the paper published yesterday has done the entire system in a dish.  They tried three types of stem cells, including stem cells from an adult (fibroblast cells).  This research, in mouse and human, will help us learn about the key processes of making an egg.

A parallel report on making sperm from stem cells was published earlier this year.

If this work is optimised in human cells, it has the potential of ‘curing’ female age-related infertility.  It may be possible to take adult cells (eg skin cells), convert them into stem cells (induced pluripotent stem cells), convert these stem cells into primordial germ cells and finally mature eggs which could be used to make a viable human embryo.

What do you think?  Is this pushing technology too far?  Or is it a great advance?

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Read the abstract of the paper here

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