Any future astronauts here who are hoping to make the first space baby might want to think again - embryonic stem cells don't act the same way in zero gravity, making successful procreation in space almost impossible.
We already know that full-grown adults suffer harmful consequences the longer they stay in microgravity, as prolonged living in zero-G causes muscles and bones to weaken and an irregular heartbeat. But the dangers also operate on much tinier scales as well, as a team of Australian researchers have now discovered. Microgravity tampers with stem cells, the building blocks of all other cells in our body and a vital repair system.
The researchers simulated zero-G conditions on Earth and then placed embryonic stem cells inside. They discovered that 64 percent of the stem cell proteins were fundamentally different from how they would be in normal gravity. And the changes weren't good - most of the altered proteins would weaken bones and allow increased oxidative damage to DNA. Damage was also done to proteins involved with the immune system, proper cell division, calcium levels, and much more.
Tissue engineer and lead researcher Helder Marcal says this is bad news for procreation in space:
"The simulated microgravity experiments we are investigating don't seem to suggest a very positive outcome. The effect that microgravity may have on a growing embryo or fetus would be similar to an adult body - however, much more detrimental. The adult body can adapt to some microgravity space environments - however, what remains totally unknown is if an embryo can adapt to such an environment too."
Still, now that we know the problems, we have a chance to solve them. Marcal says that gravity is somehow responsible for a vital part of the body's mechanical or circulatory feedback, which help keep bones and blood vessels healthy. If we can isolate exactly what gravity does, it may be possible to genetically engineer something that can substitute for the lack of gravity.
And that's a good thing for future space babies, because Marcal considers them a matter of when, not if:
"Human procreation in space is inevitable, I believe. Therapeutic and pharmaceutical intervention may not be the optimum outcome. Humans may have to consider that in the not so distant future, genetic engineering our bodies may be the way forward if we are to explore planets in our solar system. However, this raises other ethical and moral issues."