'Healthy' mouse pups born from sperm stored on International Space Station for 6 years

A team of Japanese researchers found that mouse sperm exposed to high levels of cosmic radiation produced a large brood of healthy “space pups”. In their study, which was published in Science Advances, the team said that they stored the sperms at the International Space Station (ISS) in freeze-dried form for nearly six years. Once brought back to earth and rehydrated, the sperms developed into 168 mouse pups, all of whom showed no signs of genetic defects, as per the team. Speaking in the aftermath, researchers said that all the newborns are “normal” looking and showed no difference from the mice confined to the earth.

The research began in 2013 after Japanese researcher Wakayama along with his colleagues from the University of Japan launched three boxes to outer space. Each box contained 48 ampoules of freeze-dried sperms which were then stored at the ISS. The sperms were brought back to earth for fertilization after the first nine months, then after two years, and finally after six years, leading to hundreds of births. When the space mice reached adulthood, they were randomly mated and the next generation appeared normal as well.

Could help humans 

According to the researchers, the aim of the experiment was to analyse if exposure to cosmic radiations altered DNA. The research, they said, could prove useful for our own generation in the coming space-age, which holds the potential of intra planetary migration. They added that humans could also need to spread their genetic resources off-planet in case Earth gets destructed by humankind.

"In the future, when the time comes to migrate to other planets, we will need to maintain the diversity of genetic resources, not only for humans but also for pets and domestic animals," Wakayama and colleagues wrote in their paper. "For cost and safety reasons, it is likely that stored germ cells will be transported by spaceships rather than by living animals."

Image: Teruhiko Wakayama/University of Yamanashi