Mouse embryos grown in space for first time, Japan researchers say

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 Center, and a team from the Japan Aerospace Space Agency (JAXA), sent frozen mouse embryos on board a rocket to the ISS in August 2021.

The astronauts on the station thawed the embryos using a device specially designed for this purpose, and implanted them on the station for four days.

The scientists noted that "embryos that grew in microgravity conditions naturally developed into blastocysts." Blastocysts are cells that develop into an embryo and placenta.

The researchers pointed out in a study published on the website of the scientific journal "I Science" on Saturday that the experiment "clearly demonstrated that gravity does not have a significant effect" on the issue of rat reproduction.

They noted that there were no significant changes in the state of DNA and genes, after analyzing the blastocysts that were returned to laboratories on Earth.

Yamanashi University and the Riken National Research Institute confirmed in a joint statement on Saturday that this “study is the first research work to show that mammals may be able to reproduce in space.”

The statement added, "This is the first experiment in the world to develop early-stage mammalian embryos in complete microgravity on the International Space Station."

He continued, "In the future, it will be necessary on the International Space Station to grow blastocysts in microgravity inside mice to see if these animals are able to give birth to young ones," with the aim of confirming that the blastocysts are normal.

This research is of great importance for future space missions.

Within the framework of the "Artemis" program, the US Space Agency (NASA) intends to send humans back to the moon to learn how to live there in the long term, and to prepare for a trip to Mars in the late 2030s.