18 October 2016
In something of a first, a team from Kyushu University Japan have created fully functional mice eggs from stem cells in a dish, raising questions about future potential use in humans.
Viable eggs and sperm have been created using stem cells before. But Katsuhiko Hayashi and his team took it one step further, following on from Hayashi's previous work where they created eggs and sperm which required transplantation into a host to allow them to mature in vivo. The new technique allows the process to take place entirely in a culture dish - resulting in viable eggs and 26 healthy baby mice.
The paper, published in Nature, details the process which Katsuhiko’s team developed, producing eggs from both embryonic stem cells and induced pluripotent stem cells derived from skin cells, which were developed in a culture including cells taken from the ovaries of mouse foetuses to create an ovary-like support for egg development.
Although imperfect – when used in mouse IVF, only 3.5% of these fertilised eggs resulted in a pup being born – Hayashi’s teams approach is a huge step forwards, and whilst implementation in humans may be a long way off there are a range of ethical questions that need to be resolved beforehand.
In the meantime Hayashi plans to continue studying egg development, but not with human eggs, as Japanese guidelines forbid it. Still, as stem cell science advances, it seems likely that others will try in his place, meaning that a robust debate about the issues surrounding the potential human use of this technology is needed now more than ever.
Have a look at the PHG Foundation’s healthcare futures series on Stem Cell therapy.