For the first time, mouse embryos have been successfully cultivated on the International Space Station (ISS) in a ground-breaking experiment.
Under the direction of Professor Teruhiko Wakayama of the University of Yamanashi in Japan, this ground-breaking study attempts to investigate the viability of human reproduction in space.
An article in New Scientist states that the study began with the removal of early two-cell stage embryos from pregnant mice. The embryos were then frozen and sent to the International Space Station (ISS) using a SpaceX rocket that was launched from Florida in August 2021.
The embryos were kept in specially made containers that made it simple for astronauts to defrost and cultivate them. The embryos were chemically preserved and sent back to Earth after four days.
Since embryos may only live outside of a uterus for this long, the four-day cultivation time was chosen. After returning to Earth, the scientists studied the embryos to see if the lower gravity and increased radiation in space, known as microgravity, had affected the embryos’ growth.
Despite their brief sojourn in space, the embryos did not exhibit any evidence of radiation-induced DNA damage, which was unexpected. Additionally, they showed signs of normal structural development, differentiating into the two cell groups that make up the placenta and fetus. This is especially important because it was thought that microgravity would prevent embryos from dividing into these two distinct cell types.
Studies on pregnant rats sent on NASA spaceflights suggest that normal development is conceivable, even though it is still unclear whether later phases of embryo development would be disturbed in space. When these rats returned to Earth, they gave birth to typical-weight pups, demonstrating that their gestation in space had gone according to plan.
Wakayama told New Scientist that “perhaps mammalian space reproduction is possible” in light of the findings. He did admit, though, that there are still unknowns around the actual full-term birth of a human baby or mouse pup in microgravity.
The next step for Wakayama’s team is to investigate if mouse embryos that were sent to the International Space Station (ISS) and later returned to Earth can implant in female mice and grow into healthy children.
This will shed further light on the survivability of embryos exposed to microgravity and radiation in space. Whether mouse sperm and eggs can be used for in-vitro fertilization (IVF) in space to generate embryos is another goal of the study team.