Researchers from Japan suggest that it may be possible to grow male and female reproductive cells from the opposite gender in future - in other words, to create sperm from women and eggs from men.
Katsuhiko Hayashi of Kyoto University in Japan has published research in which skin cells from mice were used to create primordial germ cells or PGCs.
These cells, the common precursor of both male and female sex cells, were then developed into both sperm and eggs. Using these live-births were created via in vitro fertilisation.
Although the techniques involved are still in their infancy, the possibilities for reproductive medicine are startling.
Not only could the research of Hayashi and his senior professor Mitinori Saitou allow infertile women to have babies by creating eggs from their skin cells, but it might make it possible for sperm and eggs cells to be created from either males or females.
The research is published in the journal Scientific American.