Rat sperm exposed to weightlessness still produces healthy rats

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An experiment that flew on ISS has found that rat sperm exposed to weightlessness and space radiation and then used on Earth to fertilize eggs still produce healthy rats.

The first issue for the researchers was how best to get the sperm up there. They decided to have the samples freeze-dried, just like instant coffee. This meant the sperm weighed almost nothing and could be kept at room temperature, ideal for travel on a rocket, or on a distant planet. The mouse sperm then spent 288 days on the ISS before coming back to Earth to be compared with fresh sperm from the same mice.

First, the scientists analysed how space travel affected the integrity of the DNA within the sperm. We know that high levels of fragmentation of sperm DNA are associated with male infertility. As expected, the scientists discovered that the space sperm had higher amounts of fragmented DNA than the sperm which had stayed on Earth. However, when used to fertilise a mouse egg, the space sperm resulted in a similar number of healthy embryos being generated – and these offspring had the ability to develop into normal, fertile adult mice. A final test the researchers did was to compare the patterns of genes being expressed within the brains of the adult mice. Here, the researchers saw no overall differences and concluded the space sperm was equally capable of generating offspring.

Obviously, this result is encouraging, but we are still a long way from nonchalantly letting women get pregnant and give birth in space. The risks on the child remain too great and are unknown.

In fact, I suspect the first time a child is born and raised in space will be an event that is unplanned.



  • wayne

    Mr. Z., — hhhmmm. Not sure about that last thought. Have not really pondered that too deeply. I am sure however, if you put boys & girls together, they inevitably do what boys & girls do.

    Q: Is somebody breeding fruit-flies on the ISS?

    Pivoting slightly, this brings to mind a fairly good SF tale of cloning vs. sexual reproduction in a post apocalyptic world.
    “Where Late the Sweet Birds Sang”
    Kate Wilhelm 1976

    (tangential references to ‘environmental collapse’ & the ‘impending Ice Age’ as well, but the story concentrates primarily on the interaction between the clones & those were are not cloned.)

  • PeterF

    The fragmentation automatically removes those sperm from the gene pool. usually only the most highly motile sperm are able to reach the egg first.

  • ken anthony

    There’s nothing wrong with imagining things going wrong and no limit to the potential problems that could be identified that way. The problem is asserting a problem exist where it’s never been demonstrated, It’s not enough to provide an example under certain conditions when the same example can be shown where those conditions don’t exist. Sometimes the rewards are much greater than the risks. People are going to die. Progress requires it.

    This in NO WAY recommends not taking precautions or doing research. But being paralyzed by imagined boogie men is just stupid and destroys growth.

  • Dick Eagleson


    I think you need to back your twit filters off about half a turn. You’re getting false positives.

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