A study of spermatozoan swimming stability near a surface

Ishimoto, Kenta; Gaffney, Eamonn A.

doi:10.1016/j.jtbi.2014.06.034

Cited by 56 publications

(72 citation statements)

References 42 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In contrast, for the hyperactivation of mouse sperm in viscous solution, where essentially straight line swimming becomes manifest [9], the potential for sperm rheotaxis is indicated, at least given boundary accumulation, though in this experimental study it is also difficult to estimate the turning circle of these sperm for more precision. The requirement for boundary accumulation however is counterindicated in previous simulations of hyperactivated sperm [17] though geometrical confinement may also be relevant for a rheotactic response. Nonetheless, this latter caveat also highlights that the complexities of boundary accumulation, such as a flagellum wavenumber dependence [16,17], are implicitly inherited by the criteria for boundary accumulating rheotaxis via the accumulation height, H.…”

Section: Discussionmentioning

confidence: 86%

Fluid flow and sperm guidance: a simulation study of hydrodynamic sperm rheotaxis

Ishimoto

Gaffney

2015

J. R. Soc. Interface.

Self Cite

View full text Add to dashboard Cite

How does a sperm find its way? The study of guidance cues has fascinated sperm biologists and in particular the prospect of rheotaxis, that is a fluid flow orienting the direction of sperm swimming, has been the subject of extensive recent study, as readily motivated by the prospect that such guidance may be active in the mammalian female reproductive tract. For instance, it has been hypothesized that helical sperm flagellar beating is necessary for such guidance, whereas there is an extensive diversity of flagellar beating patterns, with planar sperm beating readily observed in human cells for example. In particular, such cells will not be guided by fluid flow according to hypothesized mechanisms for rheotaxis presented thus far. Here, using simulation methods, we investigate rheotaxis for a wide range of flagellar beat patterns. Providing the virtual sperm firstly does not possess a tightly circling trajectory in the absence of a background flow and secondly, remains within a region of low shear to prevent being washed away by the background flow, rheotaxis is generally observed with the sperm swimming into the flow together with a possible transverse velocity. Tight circling sperm motility, as observed in select hyperactivated sperm and CatSper mutants, is predicted to disrupt the rheotactic response, whereas confinement to low shear regions generally requires boundary accumulation, thus introducing subtleties in the relationship between rheotactic behaviours and the flagellar waveform and sperm characteristics. Nonetheless, such predictions suggest such rheotactic guidance may be more common and robust than previously thought, and we document simple criteria for the presence of rheotaxis that are consistent with our simulations and understanding, as well as reported observations to date.

show abstract

Section: Discussionmentioning

confidence: 86%

Fluid flow and sperm guidance: a simulation study of hydrodynamic sperm rheotaxis

Ishimoto

Gaffney

2015

J. R. Soc. Interface.

Self Cite

View full text Add to dashboard Cite

show abstract

“…These studies neglect all Brownian motion because their magnitude is estimated to be small compared with the active forces. Other works that focus on active suspensions have been published but in general they do not include Brownian fluctuations or many-body hydrodynamic interactions [19][20][21].…”

Section: Introductionmentioning

confidence: 99%

Brownian dynamics of confined suspensions of active microrollers

Usabiaga

Delmotte

Donev

2017

The Journal of Chemical Physics

View full text Add to dashboard Cite

We present a stochastic Adams-Bashforth integrator for the equations of Brownian dynamics, which has the same cost as but is more accurate than the widelyused Euler-Maruyama scheme, and uses a random finite difference to capture the stochastic drift proportional to the divergence of the configuration-dependent mobility matrix. We generate the Brownian increments using a Krylov method, and show that for particles confined to remain in the vicinity of a no-slip wall by gravity or active flows the number of iterations is independent of the number of particles.Our numerical experiments with active rollers show that the thermal fluctuations set the characteristic height of the colloids above the wall, both in the initial condition and the subsequent evolution dominated by active flows. The characteristic height in turn controls the timescale and wavelength for the development of the fingering instability.arXiv:1612.00474v3 [cond-mat.soft]

show abstract

“…The fluid flow field around the sperm and its predicted trajectory were determined via boundary element methods (BEM) [17] (Supplementary Movie 2). The computational human spermatozoon has a prolate ellipsoid head connected to a cylindrical flagellum, as shown in Fig.…”

mentioning

confidence: 99%