Scientists create eggs in the lab from scratch
SCIENTISTS have created working mammalian eggs from scratch and used them to produce healthy offspring. The new study marks the first time eggs have been made without help from an animal.
Although the research was conducted in mice and only on eggs, it shows it may be possible to use the same techniques for humans meaning it may be possible to make humans in the lab.
Once it is done for one animal, “developing similar culture systems in other species should be only a matter of technicality”, said Dr Dusko Ilic, reader in stem cell science at King’s College London.
If that happens, we might be able not only to help infertile humans but to bring back extinct animals.
However, it is likely to be many years before the technique is safe enough for humans.
And scientists and policymakers will have to overcome the ethical challenges presented by the possibility of making children without adults fertilising or carrying them.
In the experiments, the Japanese team led by Professor Katsuhiko Hayashi, from Kyushu University, used stem cells both obtained from embryos and generated from mature cells taken from the tips of mouse tails.
The latter were used to create induced pluripotent stem cells, which have the properties of e mbryonic stem cells, i n c l u d i n g the ability to transform into a multitude of different tissues.
B o t h kinds of stem cell were exposed to cocktails of chemicals and biological signals to coax them to develop into eggs.
A key part of the process was mingling the stem cells with “gonadal somatic cells” taken from 12-day-old mouse embryos.
Writing in the online edition of Nature journal, the scientists describe how follicles formed spontaneously and surrounded the early-stage eggs.
The sac-like structures house maturing eggs in the ovaries.
A number of the eggs were eventually fertilised using a standard IVF technique and the resulting embryos produced healthy, fertile offspring.
The success rate was low – just 11 out of 316 two-cell embryos ended up delivering live births. Nevertheless, British scientists working in the same field praised the Japanese achievement.
Professor Richard Anderson, from the University of Edinburgh, said: “This is the first report of anyone being able to develop fully mature and fertilisable eggs in a laboratory setting right through from the earliest stages of oocyte (egg) development.
“Although we are a long way from making artificial eggs for women at the moment, this study also provides us with a basis for experimental models to explore how eggs develop from other species, including in women.”
He added: “One day, this approach might be useful for women who have lost their fertility at an early age, as well as for improvements in more conventional infertility treatments.
“But the very careful analyses in this paper show the complexity of the process and how it is a long way from being optimised.”