The four mice — two male and two female — were sent into space aboard the Shenzhou-21 crewed spaceship on October 31.
Beijing: Of the four mice involved in a recent mission aboard China’s space station, one female has now successfully birthed healthy offspring on Earth, the Technology and Engineering Center for Space Utilization (CSU) of the Chinese Academy of Sciences (CAS) said on Saturday.
The four mice — two male and two female — were sent into space aboard the Shenzhou-21 crewed spaceship on October 31, and were housed in a specialised habitat on the space station before returning to Earth on November 14, Xinhua news agency reported.
After their return, one female conceived and later delivered nine pups on December 10. Six of the newborns have survived — a rate considered normal. Researchers have noted that the mother is nursing normally and the pups appear active and healthy.
“This mission showed that short-term space travel did not impair the reproductive capability of the mouse,” said Wang Hongmei, a researcher at the Institute of Zoology of the CAS.
“It also provides invaluable samples for the investigation of how the space environment influences early developmental stages in mammals,” Hongmei added.
The rodents were transported to China’s space station to be raised in orbit for five to seven days, marking the country’s first scientific experiments involving mammalian models in space.
As a key model animal in the field of life sciences, the mice feature several advantages — high genetic similarity to humans, small body size and short reproductive cycle, and a high amenability to genetic modification, said Huang Kun, an expert from the Technology and Engineering Center for Space Utilization of the Chinese Academy of Sciences (CAS).
“These traits make them ideal for studying physiological and pathological processes, as well as the growth, development, and reproduction of living organisms in space,” he said.
The project, jointly led by the Shanghai Institute of Technical Physics and the Institute of Zoology, both under the CAS, involved continuous multi-dimensional video monitoring of the mice throughout their stay in orbit.
The lighting inside the mice experiment facility turned on at 7 a.m. and off at 7 p.m., maintaining the same circadian rhythm as on Earth, explained Li Tianda, an associate researcher at the Institute of Zoology.
The rodent food was not only nutritionally balanced but also made it relatively hard to reduce crumbs and meet the mice’s teeth-grinding habit. A directional air flow within the facility is designed to blow hair, faeces, and other garbage into a collection container, ensuring a clean and hygienic environment for the mice, Li said.
By collecting preliminary data on stress responses and adaptation mechanisms in microgravity, the scientists aimed to use these observations to decode how weightlessness and enclosed space influence mice’s behaviours.
After completing their orbital mission, the “mice astronauts” returned to Earth aboard the Shenzhou-20 spaceship for further analysis.
Previous animal experiments conducted in the Chinese space lab involved zebra fish and fruit flies.
