A new experiment demonstrated that sperm stored on the International Space Station for roughly nine months, produced healthy baby mice. The results of the research dubbed "Space Pup" augurs wells for human beings as they look to colonize Mars in the near future.
The freeze-dried mouse sperm stored in space and the subsequent birth of healthy baby mice suggests that human births on planets such as Mars is possible.
According to NASA, this experiment is the first to analyze the impact space radiation — which is 100 times more on the ISS than on Earth — has on mammalian reproduction.
"Space Pup represents the first step towards studying the effects of space radiation on mammalian reproduction, which must be understood to sustain life beyond Earth. This starts by holding freeze-dried mouse sperm aboard the International Space Station for one, 12, and 24 months, and then fertilizing mouse eggs on Earth to produce mouse pups to study the effects of space radiation," NASA notes.
How Was The Study Conducted?
The study's purpose was to ascertain whether mammalian reproduction was possible on space. University of Yamanashi's Teruhiko Wakayama led the study.
To validate their assertions, in 2013, the researchers sent freeze-dried sperm of 12 mice to the ISS. The sperm samples were placed inside a freezer at a temperature of -95 degrees Centigrade. The sperm remained inside this freezer for 288 days. The researchers also stored the sperm from the same mice on Earth under the same temperature for 288 days.
Is Mammalian Reproduction From Space-Preserved Sperms Possible?
When the sperm samples stored on the ISS returned to Earth, the researchers checked for any possible DNA damage due to radiation. The team noticed that the space sperm, which had exposure to higher space radiation levels near the ISS, showed higher fragmented DNA vis-à-vis the sperms stored on Earth. The space sperms' DNA damage is linked with lower fertility levels and it would be impossible for the frozen-dried sperm cells to restore the same.
However, using IVF techniques, the researchers took the space sperm and injected them into new mice eggs, which were then transferred to surrogate female mice. Three weeks after the process, the researchers found that the mice produced 73 space pups. This results surprised the scientists as this number is equivalent to those a non-DNA damaged sperm would produce.
The baby mice born from the space sperm were healthy and fertile. The researchers did not find any noticeable genetic disparities between the control group mice babies and the space pups. The experiment suggests that the damage to the DNA got repaired post fertilization. Moreover, the researchers opine that there was "no ultimate effect" on the baby mice.
"Our results demonstrate that generating human or domestic animal offspring from space-preserved spermatozoa is a possibility, which should be useful when the space age arrives," Wakayama, the study's lead author revealed.
Doomsday Vault In Space?
The researchers shared that this technology may aid in reproduction when humans reside in space for a continuous period in the near future. They noted that it is possible to preserve sperm in space for nine months. The findings hint at the likelihood of a "doomsday vault" in space, where sperm can be stored to aid in the preservation of Earth's animal species such as Norway's Global Seed Vault.
The team revealed that the next step is to send the embryos to the ISS and attempt to culture them in microgravity.
The study's findings were published in the journal Proceedings of the National Academy of Sciences on May 22.