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| Sperm Movement |
Mating of sperm with ovum is a critical event to born a baby. To complete the event, human sperm have to swim a very long distance equivalent to climbing Mount Everest. Millions of sperm try to complete the inaccessible journey by wiggling their tail to swim forward in the fluid. Finally a single sperm can achive it, in order to fertilize the egg that eventually born a baby.
But the latest discovery shows that the sperm’s tail is not swim in a way which we know. Let’s discuss the discovery.
History
Sperm was first discovered in 1677 by Antonie van Leeuwenhoek. He saw the sperm under the microscope and describe it as a “living animalcule” with a tail.
Later, scientists talked about the sperm motility, explained that how sperm swim in the fluid. They used 2D microscope to observe the behavior of Sperm during swimming. The sperms swim in the fluid by wiggling their tail from side-to-side to move forward.
From that, our perception of how sperm swim has unchanged. If we using a morden microscope today, still make the same observation. At present Computer-Assisted Semen Analysis (CASA) system is also used in 2D views of sperm movement in clinic and for research.
Leatest Research
A research have conducted by Hermes Gadêlha at al. about how human sperm swim, published online July 31, 2020 in Science Advances. In this research they used 3D microscope which include a super-fast camera capable of recording Video upto 55K fps(frame rate).
Researchers using state-of-the-art 3D microscopy technology were able to mathematically reconstruct the rapid movement of the sperm tail in 3D. Their tail’s whip-like movenent is capable of beating over than 20 swimming-strokes in less than one second.
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| Sperm tail wiggling |
Using automated tracking of swiming sperm and mathematical analyses of position data Gadêlha and colleagues broke the sparm tail into two components. The result became very surprising. One of the component was wiggling to only one side of the cell. Another component rotate the sparm, balancing the one side wiggling. It means the tail of the sperm actually wiggle to only one side and to avoid swimming in circle, sperm also rotate.
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| Sperm 3D movement |
So, The experiment shows that sperm is not swim straight forward by wiggling it’s tail on two side. The tail is in fact wonky and wiggles only one side. But if it’s only oscillate at one side, it would be swimming in circle. To avoid such circuler motion sperm are rolling as they move forward. The sperm body spins at the same time that its tail wiggiling around the moving direction.
Actually, this highly synchronised spining causes an optical illusion if we seen from above with 2D microscope.
Conclusion
The motility of human sperm perform by a complex 3D movement. Sperm drills into fluid in the helical manner. This leatest discovery, using novel 3D microscope technology along with mathematics, make fresh hope to unfold the secrets of human reproduction and may inform about diagonosis and treatment of human infertility.
thanks. to give the new concept