Tag Archives: motility

Revealing the Secrets of Motility in Archaea

Scientists from Berkeley Lab and the Max Planck Institute for Terrestrial Microbiology analyze a unique microbial motor

The protein structure of the motor that propels archaea has been characterized for the first time by a team of scientists from the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) and Germany’s Max Planck Institute (MPI) for Terrestrial Microbiology.

The motility structure of this third domain of life has long been called a flagellum, a whip-like filament that, like the well-studied bacterial flagellum, rotates like a propeller. But although the archaeal structure has a similar function, it is so profoundly different in structure, genetics, and evolution that the researchers argue it deserves its own name: archaellum. (more…)

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Sperm Length Variation is not a Good Sign

A new study published online in the journal Human Reproduction finds that the greater the inconsistency in the length of sperm, particularly in the tail (flagellum), the lower the concentration of sperm that can swim well. The finding offers fertility clinicians a potential new marker for fertility trouble that might trace back to how a patient’s sperm are being made.

PROVIDENCE, R.I. [Brown University] — Perhaps variety is the very spice of life, but as a matter of producing human life, it could be the bane of existence. That’s the indication of a new study in the journal Human Reproduction that found men with wider variation in sperm length, particularly in the flagellum, had lower concentrations of sperm that could swim well. Those with more consistently made sperm seemed to have more capable ones.

“Our study reveals that men who produce higher concentrations of competent swimming sperm also demonstrate less variation in the size and shape of those sperm,” said Jim Mossman, a postdoctoral scholar at Brown University and lead author of the paper published in advance online Oct. 28. “It suggests that in some cases, testes are working more optimally to produce high numbers of consistently manufactured sperm, and vice versa.” (more…)

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