What came first, the mouse or the egg?
A team led by researchers at Kyushu University produced functional mouse eggs and stem cells entirely in a dish thanks to an innovative cell culture system. The findings open up possibilities in the fertility and regenerative medicine fields.
The researchers took either undifferentiated stem cells from mouse embryos or stem cells reprogrammed from adult cells, and generated immature eggs called ‘oocytes’. They were then able to grow and fertilize these oocytes while they were still in a dish. When transferred to mice wombs, a small proportion (3.5 per cent) of these embryos developed into healthy fertile animals, which shows that some of the eggs were functional. The researchers also isolated stem cells from the fertilized eggs and turned them into oocytes – thus achieving a full, self-sustaining cell culture cycle.
Although it is early days, some researchers hope that these findings will help researchers working in human fertility.
- Nature 539,299–303 (2016). doi: 10.1038/nature20104