Flexural Rigidity of Echinoderm Sperm Flagella.

Flexural rigidity of echinoderm sperm flagella.

The stiffness (flexural rigidity) of live sperm flagella, Triton-demembranated flagella (axonemes), trypsin-digested axonemes, and doublet microtubules of the axonemes in echinoderms was determined from the relationship between their deformation when a stream of medium was applied and the viscous resistance of the medium acting on the flagellum. The stiffness of the flagellum beating in seawate...

Asymmetric waveforms in echinoderm sperm flagella.

1.Dark-field, multiple-exposure photographs of live spermatozoa of a number of echinoderms were analysed. 2. Bends develop at the base in pairs, as they do in flagella with symmetrical waveforms. However, the angles of these bends do not cancel, so that microtubular sliding-of up to over 50% of that associated with bend propagation-is transferred distally. This sliding implies that (a) microtub...

Direct Measurements of the Stiffness of Echinoderm Sperm Flagella

1. The stiffness (flexural rigidity) of some echinoderm sperm flagella was measured, using a flexible glass microneedle. 2. Values of 0-3-1 -5 x io a i N m were obtained for the stiffness of live flagella which were immobilized with COg-saturated sea water. 3. The immobilized live flagellum was uniform in stiffness along its entire length, except in a particular plane of imposed bending in whic...

Supplemental Information Flexural Rigidity and Shear Stiffness of Flagella Estimated from In- duced Bends and Counterbends

Flexural Rigidity and Shear Stiffness of Flagella Estimated from Induced Bends and Counterbends.

Motile cilia and flagella are whiplike cellular organelles that bend actively to propel cells or move fluid in passages such as airways, brain ventricles, and the oviduct. Efficient motile function of cilia and flagella depends on coordinated interactions between active forces from an array of motor proteins and passive mechanical resistance from the complex cytoskeletal structure (the axoneme)...