Japanese researchers at Kyoto University carried out a unique experiment on the International Space Station: for the first time, they tested how progenitor stem cells of sperm behave after a long stay in space.
Mouse cells were frozen, spent six months in orbit, and were then returned to Earth. After being transplanted into ordinary laboratory mice, these cells helped produce healthy offspring with no gene abnormalities.
Earlier, scientists had noted that cosmic radiation and microgravity could damage embryonic cells. However, the new experiment showed that spermatogonial stem cells are much more resilient than expected. The substances used for freezing had a more noticeable effect, but even that impact was minimal.
The study results open the way to future "genetic banks" in space. Of course, it is still a long way from applying such technologies to humans: researchers will need to track not only the first generation, but also later descendants. Still, the very fact that cells retained the ability to give rise to life after half a year in orbit has already become a major scientific breakthrough.
