Hydrodynamics of the double-wave structure of insect spermatozoa flagella.
In addition to conventional planar and helical flagellar waves, insect sperm flagella have also been observed to display a double-wave structure characterized by the presence of two superimposed helical waves. In this paper, we present a hydrodynamic investigation of the locomotion of insect spermatozoa exhibiting the double-wave structure, idealized here as superhelical waves. Resolving the hydrodynamic interactions with a non-local slender body theory, we predict the swimming kinematics of these superhelical swimmers based on experimentally collected geometric and kinematic data. Our consideration provides insight into the relative contributions of the major and minor helical waves to swimming; namely, propulsion is owing primarily to the minor wave, with negligible contribution from the major wave. We also explore the dependence of the propulsion speed on geometric and kinematic parameters, revealing counterintuitive results, particularly for the case when the minor and major helical structures are of opposite chirality.
Department of Mechanical and Aerospace Engineering, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0411, USA.
On Shun
OS
Pak
Saverio E
SE
Spagnolie
Eric
E
Lauga
D000818:Animals; D057446:Hydrodynamics; D007313:Insecta / Q000502:physiology* / Q000648:ultrastructure; D008297:Male; D013081:Sperm Motility / Q000502:physiology*; D013082:Sperm Tail / Q000502:physiology* / Q000648:ultrastructure