In most mammals, it takes more than month to complete the complex, multistage process of making sperm — which is why scientists have had trouble growing sperm cells in the lab. But now Japanese researchers report success, using testicular tissue from baby mice to make sperm in a lab dish and then producing healthy offspring.
With further study into the safety and efficacy of the technique in human cells, it may potentially lead to treatments for some men who suffer from infertility problems. A better understanding of how sperm form could also help improve diagnosis and treatment of male infertility.
Researchers from Yokohama City University Graduate School of Medicine in Japan published their mouse-study findings this week in Nature, noting that they hoped their discovery would eventually be able to help humans. The BBC described the scientists’ technique:
Rather than working with individual cells, the team in Japan used fragments of testes. It is like starting with a whole segment of an orange rather than just the juice.
The fragments were then bathed in nutrients and sperm production was maintained for more than two months.
The findings suggest that testicular tissue can be frozen and saved for later use — a potential advance that could help preserve fertility in certain patients, such as young boys facing cancer treatment. Adult cancer patients can freeze sperm before starting chemotherapy or radiation, but that isn’t an option for boys who haven’t entered puberty yet.
Experts caution, however, that while the experimental advance is significant, there needs to be much more research before a similar technique could be used in the clinic. “It is important to be cautious because sometimes species-specific differences in biology means that what works for one species does not work in another,” Dr. Allan Pacey, a senior lecturer in andrology at the University of Sheffield, told the BBC.