Space radiation in particular is a major concern for countries like the United States and Japan, which have sent many astronauts on long missions into low Earth orbit. And not only that. There are other space destinations on the horizon and NASA and other space agencies are developing systems that could help humans on months-long journeys to other destinations in the solar system such as the Moon and Mars, where radiation is a major concern. that radiation on the International Space Station is more than 100 times stronger than on Earth.
Now a study published in the journal Science Advances shows that freeze-dried mouse sperm that spent months on the International Space Station (ISS) and returned to Earth successfully fertilized mouse eggs to produce healthy mouse “space babies.” , for science. It is the longest biological experiment conducted on the ISS to date.
Sperm appear to be undisturbed by long periods in outer space.
The Japanese researchers behind the new work wanted to know how space radiation affects fertility in mammals. Radiation can damage DNA within cells and cause mutations, defects in the offspring of animals.
“It is very important to examine the effects of space radiation not only on living organisms, but also on future generations before the ‘space age’ arrives,” the authors wrote. “Space radiation can cause DNA damage in cells and concern about inheritance of mutations in offspring after deep space exploration.”
How was the experiment done?
Instruments on Earth cannot masterfully mimic space radiation, and the ISS lacks freezers for long-term cell storage; So biologist Teruhiko Wakayama of Yamanashi University in Kōfu, Japan, and his colleagues lyophilized the sperm, allowing it to be stored at room temperature. Then, they sent the sperm from 12 mice to the space station , while keeping other sperm from the same mice on the surface.
After returning the sperm to Earth, rehydrating them, and injecting them into fresh mouse eggs, the team transferred those embryos to female mice. Approximately 240 healthy space mouse pups were born from sperm stored on the ISS for nearly three years; about 170 more were born from sperm stored on the space station for nearly six years. Genetic analyzes revealed no differences between these space mice and mice born from sperm stored on Earth. The “space mice” that mated into adulthood had healthy offspring as well.
Promising results
If human sperm is just as tough in space, something that may have to do with a lack of water in sperm, and if the Earth becomes uninhabitable in the future, then freeze-dried sperm could potentially play a role. in the repopulation of space colonies.
Referencia: Sayaka Wakayama et al, Evaluating the long-term effect of space radiation on the reproductive normality of mammalian sperm preserved on the International Space Station, Science Advances (2021). DOI: 10.1126/sciadv.abg5554
