Mouse sperm survives in space, but could human babies?

MI A M I: Freeze-dried mouse sperm that spent nine months in space has been used to produce healthy rodent offspring back on Earth, Japanese researchers said.

But, could the same hold true for humans? And, if conception were even possible in space, would babies born in zero gravity develop differently than their Earth-bound counterparts?

As National Aeronautics and Space Administration and other global space agencies work on propelling people to Mars by the 2030s, experts say essential questions of survival on the Red Planet are often overlooked.

A key component to colonising other planets would be having babies, said Kris Lehnhardt, assistant professor in emergency medicine at The George Washington University School of Medicine and Health Sciences.

“If your goal is to eventually be a truly space-faring species, then this is an essential area to study.

“It is a completely unknown area of science.”

A study in Monday’s edition of the Proceedings of the National Academy of Sciences was an “interesting step”, said Lehnhardt.

Mouse sperm was freeze-dried and sent for nine months to the International Space Station 400km above Earth.

When the shipment returned, lead researcher Teruhiko Wakayama of the University of Yamanashi found the space sperm had sustained “slightly increased DNA damage”, after enduring an average daily radiation dose about 100 times stronger than on Earth.

Back on Earth, embryos fertilised in-vitro with the sperm produced healthy offspring, and grew into normal adults, “suggesting that the DNA damage observed in the space-preserved sperm samples was largely repaired in embryos after fertilisation”, said the report.

For researchers who examined the effect of deep space radiation on the reproductive organs of female mice, the news is not good.

A study published in the journal Reproduction this month showed that damage to the ovaries of female mice exposed to charged particles is typical of space radiation, “raising concern for premature ovarian failure in astronauts” exposed to deep space travel, it said.

“These types of exposures can cause early ovarian failure and cancer, as well as osteoporosis, cardiovascular disease and neurocognitive diseases like Alzheimer’s,” said one of the study’s authors, Ulrike Luderer, a professor of medicine at the University of California in Irvine.

“Half the astronauts in the Nasa’s new classes are women. So it is important to know what health effects there could be for women exposed to long-term deep space radiation.” AFP