Mouse embryos（胚胎） have been cultured（培养） on the International Space Station (ISS), marking a significant step in understanding reproduction in space. Led by Teruhiko Wakayama from the University of Yamanashi in Japan, this experiment studied the possible safety of human pregnancy（怀孕） during long space journeys, such as a trip to Mars that lasts more than six months. Wakayama emphasized the importance of this research, saying, "We are conducting research to ensure we will be able to safely have children if that time comes."
The experiment began on Earth, where early two-cell stage embryos from pregnant mice were taken out, frozen, and sent to the ISS on a SpaceX rocket. Astronauts on the ISS then warmed up and cultured the embryos for four days using devices specially designed for this task. Afterward, the embryos were kept and returned to Earth. The four-day growth period was chosen as embryos can only survive for this length outside a uterus, according to Wakayama.
Upon their return, the embryos were examined to check the impact of space's unique conditions, such as higher radiation（辐射） levels and microgravity（微重力). The results were promising; the embryos showed no DNA damage from radiation and showed normal structural development, including the crucial change into two cell groups necessary for forming the fetus and placenta. Wakayama found these results significant, as it was previously believed that microgravity might prevent the embryo's ability to separate into these separate cell types.
While these findings are promising, further research is needed to fully understand space reproduction. Wakayama referred to a previous study involving pregnant rats in space, which resulted in the birth of typical-weight rats, suggesting normal development. The team now aims to further study the health of embryos exposed to space conditions and plans to test whether mouse embryos sent to the ISS can develop into healthy young after returning to Earth.
