Researchers have suggested that it may be possible in the future to create female sperm and male eggs - a feat, that if achieved, could revolutionise infertility treatments.
Katsuhiko Hayashi of Kyoto University in Japan and his senior professor Mitinori Saitou used skin cells from mice to create primordial germ cells or PGCs. PGCs are the common precursor of both male and female sex cells.
These cells were then developed into both sperm and eggs. Scientists used these to create live-births via in vitro fertilisation.
The technique offers numerous possibilities for reproductive medicine. It may allow infertile women to have babies by creating eggs from their skin cells, and also make it possible for sperm and eggs cells to be created from either males or females, 'The Independent' reported.
In the technique, pluripotent stem cells were extracted from early-stage embryos and somatic cells, and were then converted into PGCs using signalling molecules.
These germ cells were transplanted into the ovaries and testes of living mice to develop. Once these cells were mature they were extracted and used to fertilise one another in vitro.
The initial research took place in October last year, with researchers claiming that the live-births were merely a 'side effect' of the research to demonstrate that the creation of PGCs had been successful.
Other researchers have replicated the production of PGCs but could not succeed in producing live births. The scientists involved also have many other hurdles to overcome including the production of 'fragile' and 'misshapen' eggs, wrote David Cyranoski in 'Scientific American'.
The Japanese team is now working on monkey embryos and believe they could repeat the mouse work in monkeys within 5Ņ10 years, with the creation of human PGCs following shortly after.
While making PGCs for infertility treatment will be a huge jump, many scientists are urging caution as embryonic stem cells frequently pick up chromosomal abnormalities, genetic mutations and epigenetic irregularities during culture.
Hayashi has also said that a viable infertility treatment could be 10 or even 50 years in the future.
"My impression is that it is very far away. I don't want