How do sperm move? Scientists have apparently been exposed to optical illusion for centuries.
Bristol / Mexico City (dpa) – Human sperm do not move like eels, but rather like otters – the authors of a new study report.
Using modern 3D microscopy, they have disproved the more than 300-year-old assumption that the tail parts of the sperm cells move from side to side, the researchers at the English University of Bristol and the Autonomous University of Mexico City wrote in the journal Science Advances.
As early as the 17th century, the Dutchman Antoni van Leeuwenhoek had observed sperm with a simple microscope and compared their swimming movements with that of eels. This is an optical illusion, said the University of Bristol. According to the new findings, only one side of the tail winds. In order not to move in a circle, sperm turned like corkscrews, like playful otters in the water.
Through a two-dimensional microscope, the fast and synchronized rotary movements look like the tail is moving symmetrically from side to side, the university quoted the leading author of the study, Hermes Gadêlha – an expert in the field of fertility mathematics.
“Human sperm have found that their one-sided swimming movement balances and they swim forward when they roll while swimming – similar to playful otters that move through water like corkscrews,” said Gadêlha.
The sperm would have solved a mathematical puzzle on a microscopic scale by creating symmetry from asymmetry. Understanding the movement of the sperm tail is essential to identify unhealthy sperm in the future.