Flagellar synchronization through direct hydrodynamic interactions

@article{Brumley2014FlagellarST,
  title={Flagellar synchronization through direct hydrodynamic interactions},
  author={Douglas R. Brumley and Kirsty Y. Wan and Marco Polin and Raymond E. Goldstein},
  journal={eLife},
  year={2014},
  volume={3}
}
Flows generated by ensembles of flagella are crucial to development, motility and sensing, but the mechanisms behind this striking coordination remain unclear. We present novel experiments in which two micropipette-held somatic cells of Volvox carteri, with distinct intrinsic beating frequencies, are studied by high-speed imaging as a function of their separation and orientation. Analysis of time series shows that the interflagellar coupling, constrained by lack of connections between cells to… 
Elastohydrodynamic Synchronization of Adjacent Beating Flagella.
TLDR
An asymptotic analysis of the hydrodynamic coupling between two extended filaments in the regime d/L ≪ 1 is presented, and it is found that the form of the coupling is independent of the microscopic details of the internal forces that govern the motion of the individual filaments.
Metachronal waves in the flagellar beating of Volvox and their hydrodynamic origin
TLDR
It is found that random variations in the intrinsic rotor frequencies increase the robustness of the average properties of the emergent metachronal waves, and that defects result from sufficiently steep local biases in the oscillators' intrinsic frequencies.
Bistability in the synchronization of actuated microfilaments
TLDR
This work investigates the behaviour of elastic microfilaments, protruding from a surface and driven at their base by a configuration-dependent torque, and considers full hydrodynamic interactions among and within filaments and no slip at the surface.
Intracellular coupling modulates biflagellar synchrony
TLDR
This work reports that basal coupling is sufficient to achieve inphase, antiphase and bistable synchrony, even in the absence of hydrodynamic coupling and flagellar compliance, and shows a concrete route for cells to actively control the synchronization of their flagella.
Coordinated beating of algal flagella is mediated by basal coupling
TLDR
The insufficiency of hydrodynamic coupling is demonstrated in an evolutionarily significant range of unicellular algal species bearing multiple flagella, and it is suggested that the key additional ingredient for precise coordination of flagellar beating is provided by contractile fibers of the basal apparatus.
Hydrodynamic synchronization in strong confinement.
TLDR
It is shown that force modulation is a mechanism that leads to phase-locked states under strong confinement that are very similar to those without confinement as a difference with the elastic compliance mechanism, suggesting it could be the most essential physical mechanism overall in arrays of nodal cilia.
Hydrodynamics of flagellar swimming and synchronization
TLDR
It is proposed that direct elastic coupling between the two flagella of Chlamydomonas, as suggested by recent experiments, in combination with waveform compliance is crucial to facilitate in-phase synchronization of the twoFlagellar synchronized cells.
Spontaneous oscillations, beating patterns, and hydrodynamics of active microfilaments
TLDR
The results demonstrate the existence of a second transition far from equilibrium, where nonlinearities cause a reversal in the direction of wave propagation and produce a variety of waveforms that resemble the beating patterns of swimming spermatozoa.
Transitions in synchronization states of model cilia through basal-connection coupling
TLDR
This work focuses on the model biflagellate Chlamydomonas reinhardtii, and proposes a minimal model for the synchronization of its two flagella as a result of both hydrodynamic and direct mechanical coupling.
Control of synchronization in models of hydrodynamically coupled motile cilia
In many organisms, multiple motile cilia coordinate their beating to facilitate swimming or driving of surface flows. Simple models are required to gain a quantitative understanding of how such
...
...

References

SHOWING 1-10 OF 70 REFERENCES
Lag, lock, sync, slip: the many ‘phases’ of coupled flagella
TLDR
High-speed, high-resolution imaging of single pipette-held cells is used to quantify the rich dynamics exhibited by their flagella, and mechanically induced removal of one or the other flagellum of the same cell is revealed to reveal a striking disparity between the beatings of the cis and trans flageLLum, in isolation.
Noise and synchronization in pairs of beating eukaryotic flagella.
TLDR
It is shown that the flagella of a C. reinhardtii cell present periods of synchronization interrupted by phase slips, which are consistent with a low-dimensional stochastic model of hydrodynamically coupled oscillators, with a noise amplitude set by the intrinsic fluctuations of single flagellar beats.
Hydrodynamic synchronization of light driven microrotors.
TLDR
This work has used the combination of two-photon polymerization and holographic optical trapping to build a mesoscale model composed of chiral propellers rotated by radiation pressure and shows that the phase lag between the two microrotors is distributed according to a stationary Fokker-Planck equation for an overdamped particle over a tilted periodic potential.
Cell-body rocking is a dominant mechanism for flagellar synchronization in a swimming alga
TLDR
Realistic hydrodynamic computations and high-speed tracking experiments of swimming cells are presented that show how a perturbation from the synchronized state causes rotational motion of the cell body, which feeds back on the flagellar dynamics via hydrod dynamic friction forces and rapidly restores the synchronization state in the theory.
Hydrodynamic synchronization between objects with cyclic rigid trajectories
TLDR
A minimal model of hydrodynamic synchronization in the low Reynolds number limit of rotors, which shows that flexibility of cilia or flagella is not a requisite for their synchronized motion, in contrast to previous expectations.
Generic conditions for hydrodynamic synchronization.
TLDR
A model of rigid-body rotors making fixed trajectories of arbitrary shape under driving forces that are arbitrary functions of the phase is studied to obtain the necessary and sufficient conditions for synchronization of a pair of rotors.
Antiphase synchronization in a flagellar-dominance mutant of Chlamydomonas.
TLDR
The discovery is reported that ptx1, a flagellar-dominance mutant of C. reinhardtii, can exhibit synchronization in precise antiphase, as in the freestyle swimming stroke, and that the latter has a distinct waveform and significantly higher frequency.
Spontaneous creation of macroscopic flow and metachronal waves in an array of cilia.
TLDR
It is shown that an aligned array of cilia is able to spontaneously break the left-right symmetry and to create a global average flow, which might be its major advantage.
Flagellar synchronization independent of hydrodynamic interactions.
TLDR
It is shown that perfect synchronization between these two driven spheres can occur due to the motion of the swimmer and local hydrodynamic friction forces.
Emergence of metachronal waves in cilia arrays
TLDR
It is shown that hydrodynamic interactions are indeed sufficient to explain the self-organization of MCWs and beat patterns, stability, energy expenditure, and transport properties are studied, which can be a vital advantage for ciliated organisms.
...
...