Mouse embryos grown in space for first time: Japan researchers

Mouse embryos have been grown on the International Space Station and developed normally in the first study indicating it could be possible for humans to reproduce in space, a group of Japanese scientists said.

The researchers, including Teruhiko Wakayama, professor of University of Yamanashi's Advanced Biotechnology Centre, and a team from the Japan Aerospace Space Agency (JAXA), sent frozen mouse embryos on board a rocket to the ISS in August 2021.

Astronauts thawed the early-stage embryos using a special device designed for this purpose and grew them on the station for four days. "The embryos cultured under microgravity conditions developed" normally into blastocysts, cells that develop into the fetus and placenta, the scientists said.

The experiment "clearly demonstrated that gravity had no significant effect," the researchers said in a study that was published online in the scientific journal iScience on Saturday. They also said there were no significant changes in condition of the DNA and genes, after they analyzed the blastocysts that were sent back to their laboratories on Earth.

This is "the first-ever study that shows mammals may be able to thrive in space," University of Yamanashi and national research institute Riken said in a joint statement on Saturday. It is "the world's first experiment that cultured early-stage mammalian embryos under complete microgravity of ISS," the statement said.

Image source: NASA/Crew of Expedition 8, Wikimedia Commons, CC BY-SA 4.0.