Alien cultures might be happy to know that if we humans ever do start colonizing the universe, we may have a few problems going forth and multiplying.
A team of Japanese scientists has found that microgravity significantly lowers the birth rate in mammals, based on their study of mice embryos subjected to space-like conditions in the lab.
In previous studies in rats, scientists had seen that microgravity during space flight lowered sperm counts and even caused the poor rodents' testicles to weigh less. [Rat-testicle weigher sounds like a job for Mike Rowe to me!]
Meanwhile, mouse-embryo cells flown aboard the space shuttle Columbia in 1996 failed to yield any mousey babies.
Reporting in the open-access journal PLoS ONE, Sayaka Wakayama, of the Laboratory for Genomic Reprogramming in Kobe, and colleagues note that the issue warrants further study, but sending actual mice into space and seeing if they breed presents a few challenges.
"If mice were to be taken into space, they would be exposed to strong vibrations and hypergravity during the launch, and then suddenly exposed to the additional stress of µG conditions. In these situations, it is highly unlikely that the mice would copulate during the flight period," the study authors write.
The solution? Mouse in vitro fertilization, or IVF.
Using a device that kinda looks like a robot's rotissomat to simulate microgravity, the scientists fertilized mouse embryos and allowed them to develop in conditions like what they would experience in space.
The eggs were then taken out and transferred to waiting mouse moms. The fertilization part worked as expected, and the mice gave birth to 75 healthy space babies.
"All these offspring appeared normal, and randomly selected animals were later proven fertile by natural mating," the authors note.
But that's just a 35 percent birth rate, compared to the 63 percent of successfully born IVF mice that got to develop under normal Earth gravity.
Next steps, the authors say, will be to see how well embryo implantation works in space.
If a colony ever does get built on the moon or Mars, I suppose eventually we'll want to extend such studies to humans, although I'm guessing much more work will be done between now and then on whether we can make babies in space the old-fashioned way.
Any volunteers for this important medical research?
