Researchers have been successful in creating sperm-producing germ cells from stem cells in a lab and transferred them into infertile mice, which after the treatment were able to produce healthy offspring. This new development could help thousands of infertile men become fathers if the method proves similarly effective in humans.
Japanese scientists at Kyoto University used stem cells from mouse embryos to create primordial germ cells, which drive the production of sperm in men. When transplanted into the testicles of infertile mice, the cells produced normal-looking sperm. Researchers led by Dr Katsuhiko Hayashi injected the sperm into mouse eggs and implanted them into female mice, which give birth to healthy pups. The babies, when they grew up, were capable of reproducing naturally, according to a study in the Cell journal.
Earlier experiments in this area have not been so successful, and in most cases led to unhealthy offspring which soon died.
Fertility expert Dr Allan Pacey, senior lecturer in andrology at the University of Sheffield, said, “This is quite a step forward in developing a process by which sperm could be made for infertile men, perhaps by taking as a starting point a cell from their skin or from something like bone marrow. Clearly more work needs to be done to refine this process…but it's hugely exciting.”
Also UK might not have problems with this new technique because laws here ban the use of lab-made mature sperm in fertility treatments because the scientists only created germ cells which produced sperm naturally. Dr Pacey said, “The philosophy of the law is to stop that kind of thing happening. But in this case you're not technically creating sperm, so it might be that you can sidestep this regulation. It all depends on definition.”
According to Dr Jane Stewart, British Fertility Society spokesperson and consultant gynaecologist at Newcastle Fertility Centre the ability to create human sperm-producing cells in the lab would be a “landmark achievement” in fertility treatments. She added, “This publication in an animal model marks a further step towards this goal, however as the authors clearly point out much work remains to be done.”
“Continued investigations aimed at in vitro reconstitution of germ cell development, including the induction of female primordial germ cell-like cells and their descendants, will be crucial for a more comprehensive understanding of germ cell biology in general, as well as for the advancement of reproductive technology and medicine,” the researchers wrote.
Scientists transform skin cells into functional eggs in mice