Tokyo (AFP)
Will humanity ever be able to reproduce in space? Male mice that spent 35 days in the International Space Station (ISS) kept their reproductive abilities intact when they returned to Earth, Japanese researchers found.
Previous studies have shown that an extended stay in space can affect the reproductive functions of male mammals.
In particular, 9 months of frozen mouse sperm aboard the ISS had been affected by radiation, and production and sperm count had been affected in rats after 13 days in orbit.
A new Japanese study examined 12 male mice that had stayed in specially designed individual cages aboard the ISS for 35 days.
Some of these cages were in weightless conditions, while others were maintained in an environment of artificial gravity.
Researchers led by Masahito Ikawa, a professor at Osaka University, Japan, used sperm from these mice when they returned to Earth to fertilize female mouse eggs, which had not traveled to outer space. .
It turned out that their offspring were normal and healthy. Neither the reproductive system of space rodents, nor that of their descendants have been affected, revealed molecular analyzes.
"We conclude that short-term space stays do not cause damage to the physiological function of the male reproductive organs, sperm function, and the viability of offspring," says the study published in the journal Scientific Reports on Tuesday. Nature.
Medical research has already shown that space travel has harmful effects on the health of astronauts: deterioration of muscle mass and bone density, visual disturbances and genome mutations.
Previous studies have observed the consequences of space travel on the reproductive systems of other animals, including sea urchins and birds. But this is the first time a study has analyzed these effects at such a detailed level on mammals.
But research is still in its infancy, and the results of this study can not extrapolate to humans.
"Further analysis is needed to examine the long-term effects of the space environment on the male reproductive system," say the authors of the Japanese study, which did not include female mice.
© 2019 AFP