Scientists Disprove 340-Year-Old Belief on How Sperm Moves: Apparently, They Like to Spin

Researchers from Bristol and Mexico made a breakthrough in fertility science when they disproved the centuries-old belief of how the sperms swim.

Dutch textile merchant Antonie van Leeuwenhoek invented the powerful compound microscope around 340 years ago. He accidentally discovered the single-cell bacteria, which changed the course of medicine.

Shortly after that, he examined his own semen and found tiny, wriggling creatures called "animalcules."

In 1678, van Leeuwenhoek wrote to the secretary of the Royal Society in London that the creatures he discovered moved forward as their tails move like that of a snake or an eel swimming in water.

He described the tail of the sperm as moving like how snakes or eels do when swimming. This was confirmed by scientists over the next centuries while observing the sperms under the microscope. Since then, science has believed that sperms wriggle as they swim.

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Sperms Deceived Scientists for 340 Years

Now, it turns out that the centuries-long belief of how sperms swim is wrong. Using state-of-the-art 3D microscopy and mathematics, scientists found that sperms swim like the otters.

Study author Hermes Gadelha, head of Polymaths Laboratory in the department of engineering mathematics at the University of Bristol, sperms are very tricky creatures deceiving scientists for so long.

Gadelha noted that to see the real movement of the tail, one should "move with the sperm and rotate with the sperm." It is like putting a tiny camera on the sperm's head.

That is just how Gadelha's co-authors Gabriel Corkidi and Alberto Darszon, both from the Universidad Nacional Autonoma de Mexico.

They used state-of-the-art tools like the super-high-speed camera that can record more than 55,000 frames within a second. The researchers were successful and saw that the centuries-old belief side-to-side movement of the sperms was actually not true.

They discovered that the sperm's tail lashes to only one side, enabling them to swim in a perpetual circle, says Gadelha.

The sperms were smart enough to figure out that if they roll while swimming, like otters corkscrewing through water, their one-sided stroke will allow them to swim forwards.

"The rotation of the sperm is something that is very important. It's something that allows the sperm to regain symmetry and actually be able to go straight," Gadelha added.

Groundbreaking Study Surprises Science

Gadelha remarked that their findings were indeed a surprise. To confirm their findings, they spent nearly two years repeating the experiment and cross-checking their math equations. But the results stayed the same.

But why does the sperms' movement important in science?

Gadelha said that the rotating motion of the sperms may be hiding some subtle aspects about their health or how well they can travel so fast.

The researchers hope that more scientists and fertility experts will use their findings for future research on male fertility.

Gadelha said that the instrument that they used in this breakthrough has limitations. They are open to finding more about how the sperms move, and hopefully, they will discover more exciting details about it.