Random Thoughts

[Angrboda]

As humankind moves toward the goal of establishing a long-term presence on the moon and Mars, the question of whether reproduction is possible in extraterrestrial environments may no longer be merely hypothetical. And new research using ​simulated microgravity conditions has identified some major challenges.

Experiments conducted by scientists in Australia found that microgravity conditions, simulated in a laboratory, disrupt sperm navigation, reduce ‌fertilization rates and, when exposure is prolonged, compromise the quality and survival of early embryos.

They found that human and mouse sperm cells were around 50% less effective at swimming through a channel mimicking the female reproductive tract under these conditions compared to normal gravity. In mouse eggs, this translated into a drop of roughly 30% in fertilization success. The research also revealed complications in early embryo development.

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"It is not the ability to swim that is affected. Sperm in microgravity still move, they just cannot find their way. The function ​that appears to be disrupted is navigation, the ability to orient and move with purpose toward a destination. We believe this happens because many of the proteins on the surface of sperm act as ‌mechanosensors, tiny ⁠molecular devices that detect physical forces including gravity," McPherson said.

"When that gravitational pull is removed, these sensors appear to be thrown off, leaving the sperm without a reliable frame of reference for up, down or which direction to move. It is a bit like trying to navigate a maze blindfolded and spinning," McPherson said.

Outer space conditions hamper sperm's ability to navigate toward an egg