The Japanese have done it again! For the first time in human history,they have successfully utilized sperm cells created with stem-cell techniques to fertilize eggs and produce live, normal offspring.
They used embryonic stem cells of mice to make primordial germ cells,which are the precursors for sperm cells.
Scientists have for ages tried to create sperm by using stem cells in earlier in-vitro studies using mice and human cells, but up until now they haven’t been successful.
The breakthrough research by the Asian scientists, led by Professor
Mitinori Saitou from the Kyoto University, is published as an
abstract in the journal Cell,, entitled: “Reconstitution of the Mouse Germ Cell Specification Pathway in Culture by Pluripotent Stem Cells”.
They then transplanted them into the testicles of infertile mice,
after which the cells produced normal-looking sperm. The mature sperm cells were used to fertilize eggs and produced healthy, fertile offspring.
These findings will encourage further research into the process of how primordial germ cells develop, something that has been difficult to investigate because these cells don’t grow in vitro.
Whether future findings eventually will lead to new discoveries in
human fertility remains a question. Human and mouse embryonic stem cells have different properties and any research of this kind with
human stem cells will of course become an ethical issue as well.