Scientists have found that sperm benefit from cooperation as they swim to the egg, and this could lead to improved IVF treatments.
Radiologically speaking, sperm is believed to be nature’s best athlete, and is designed to win a race of the millions to get to the egg first, fertilize it and pass on its genes.
However, scientists have discovered that the most successful sperms do not act on their own, but cooperate as they travel toward the egg – and knowing how to do this could lead to better IVF treatments.
Researchers have found biological benefits to sperm working together that may have implications for fertility studies.
It turns out that sperm literally “hold on” as they struggle to swim against a stream of thick fluid on their journey toward the egg.
Scientists say they often cooperate to navigate the female tracts of many mammalian species. It was reported in Science magazine Frontiers in Cellular and Developmental Biology About the reasons for the attachment of sperm.
The physics of how they are transmitted to an egg in mammals, including humans, is now well understood.
Scientists have found that sperm tend to clump together — in a non-random fashion — as they swim through the thick, flexible fluid in the female reproductive system.
“This may resemble the formation of a peloton in cycling, although the fluid mechanics of sperm is different from that of motorcyclists,” said Dr.
The scientists used bovine sperm – similar to that of humans – and a device that mimics the composition of the female reproductive system in order to observe how well sperms sticking together in the thick, flexible fluid are able to swim against different flow currents.
Researchers have found three biological benefits for sperm clumps together rather than swimming to an egg alone.
In the absence of a current, the staphylococcal sperm swam in a straight line; Against a moderate or moderate current, the sperm were better aligned, like a group of fish heading upstream; And against the strong flow, staphylococcal sperm were less likely to move away.
“Our finding of the biological advantages of sperm swimming together suggests that, at least in some parts of the female reproductive system, it is a good idea for sperm to cooperate with one another,” said Dr. Tong.
The findings from the sperm collaboration do not surprise Dr Edgar V. Mokano, Consultant Obstetrician and Gynecologist from Rotunda Hospital in Dublin and the Royal College of Surgeons in Ireland.
“Ejaculate contains millions of sperm,” said Dr. Mukano, who specializes in reproductive medicine and surgery.
The task is not a single missile, but the formation of combat aircraft.
“The goal is not to find a single egg, but to get into the fallopian tubes and wait patiently for the egg to appear.
“The efficiency of the sperm is not in the speed, but in the continuous progression of the tubes, so swimming in the formation makes a lot of sense.”
Dr. Mukano said human infertility is a problem in the man in one third of cases, and in another third in the woman. In the rest the cause is unknown.
He believes this new knowledge about how sperm cooperate could lead to new and better ways to treat infertility.
This could be accomplished, Dr. Mukano said, “by identifying better methods for semen sample analysis, better ways to assess the ‘swimming ability’ of sperm in the laboratory, as well as improving the selection of more efficient sperm for assisted reproductive treatments.”
“We certainly hope that the knowledge we provide here will lead to a better diagnosis of male infertility,” said Dr. Tong.