Teams of sperm huddle together like a biker’s pack to fight vaginal fluid

A new study has found that our young swimmers aren’t lonely wolves as we once thought – sperm cells tend to clump together so they can easily cross vaginal fluid.

It has long been portrayed that the strongest and fittest sperms outperform all other sperm in the fertilization race. That may be true, but the amount of collaboration with his fellow sperm populations has surprised scientists.

New research now shows that Sperm (also known as sperms) they work together to navigate the treacherous female reproductive system in a wide variety of mammalian species. previouslyIt has been baffling to scientists why sperm seem to naturally clump together without sticking when swimming in the reproductive tract.

Reproductive fluid in the cervix, uterus, and oviduct (where the egg is fertilized) can be a tricky thing to maneuver – imagine trying to swim through a melting vessel. cheese. It was found that single swimmers do not outperform packers in these settings. This seems to be so useful that the wood rat’s sperm heads actually have a hook to attach to their neighbours. This can help create huge “sperm trains” that may contain hundreds of thousands of individual sperm cells.

To investigate this lumpy feature further, the researchers had to develop a system that was not as two-dimensional as an ordinary microscopic slide. They used bovine sperm (because it was a good model for comparison with human sperm) and had a device used to mimic the female organ. The researchers looked at groups of sperm in different flow scenarios.

When there is no outflow, groups of sperm swim in a straight line and shift less than individuals. In moderate flow, they looked more harmonious, like a school salmon Heading upstream. When there is a high flow rate, the sperm tend to stick together to prevent them from being washed away by the strong current.

Single symbiosis of sperm and swimming. Staphylococcal spermatozoa are distinguished by yellow ovals. Scale bar: 50 µm. Image credit: S Phuyal, SS Suarez, CK Tung

“In general, I would say that identifying motility benefits that are not related to improving speed is not a regular thing, and therefore important. In some ways we are opening up new ways to examine sperm performance,” Dr. Chih Kwan Tong, co-author of the study, noted in a statement.

Tong came up with an amazing analogy when it comes to heavy flow individuals. “This may resemble peloton formation in Cycling, although the fluid mechanics of sperm is fundamentally different from that of cyclists. We would definitely like to know more about this.”

This study is very important. Understanding the complex physics of one of the oldest known races – the acceleration of sperm to reach the egg – could help. fertility future treatments.

“In the long term, our understanding may provide a better choice of sperm used for intervention such as in vitro fertilization or other assisted reproductive technologies,” Tong said. “This might be needed [these methods] It typically bypasses some or all of the selection mechanisms present in the female tract and leads to less favorable outcomes.”

You never know, maybe one day sperm racing will be a sport.

This study was published in the journal Frontiers in Cellular and Developmental Biology.