Ciliary beating patterns map onto a low-dimensional behavioural space

AbstractBiological systems are robust to perturbations at both the genetic and environmental levels, although these same perturbations can elicit variation in behaviour. The interplay between functional robustness and behavioural variability is exemplified at the organellar level by the beating of cilia and flagella. Cilia are motile despite wide genetic diversity between and within species, differences in intracellular concentrations of ATP and calcium, and considerable environment fluctuations in temperature and viscosity. At the same time, these perturbations result in a variety of spatio-temporal patterns that span a rich behavioural space. To investigate this behavioural space we analysed the dynamics of isolated cilia from the unicellular algae Chlamydomonas reinhardtii under many different environmental and genetic conditions. We found that, despite large changes in beat frequency and amplitude, the space of waveform shapes is low-dimensional in the sense that two features account for 80% of the observed variation. The geometry of this behavioural space accords with the predictions of a simple mechanochemical model in the low-viscosity regime. This allowed us to associate waveform shape variability with changes in only the curvature response coefficients of the dynein motors.

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Role of the Cilia Membrane in Control of Microtubule Sliding

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s1431927600002683 ◽

1980 ◽

Vol 38 ◽

pp. 612-615

Author(s):

Edna S. Kaneshiro

Keyword(s):

Control Mechanism ◽

Beat Frequency ◽

Surface Membrane ◽

Ciliary Membrane ◽

Ciliary Beating ◽

Ciliary Reversal ◽

Voltage Dependent ◽

Reversal Mechanism ◽

And Function

It is currently believed that ciliary beating results from microtubule sliding which is restricted in regions to cause bending. Cilia beat can be modified to bring about changes in beat frequency, cessation of beat and reversal in beat direction. In ciliated protozoans these modifications which determine swimming behavior have been shown to be related to intracellular (intraciliary) Ca2+ concentrations. The Ca2+ levels are in turn governed by the surface ciliary membrane which exhibits increased Ca2+ conductance (permeability) in response to depolarization. Mutants with altered behaviors have been isolated. Pawn mutants fail to exhibit reversal of the effective stroke of ciliary beat and therefore cannot swim backward. They lack the increased inward Ca2+ current in response to depolarizing stimuli. Both normal and pawn Paramecium made leaky to Ca2+ by Triton extrac¬tion of the surface membrane exhibit backward swimming only in reactivating solutions containing greater than IO-6 M Ca2+ Thus in pawns the ciliary reversal mechanism itself is left operational and only the control mechanism at the membrane is affected. The topographic location of voltage-dependent Ca2+ channels has been identified as a component of the ciliary mem¬brane since the inward Ca2+ conductance response is eliminated by deciliation and the return of the response occurs during cilia regeneration. Since the ciliary membrane has been impli¬cated in the control of Ca2+ levels in the cilium and therefore is the site of at least one kind of control of microtubule sliding, we have focused our attention on understanding the structure and function of the membrane.

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Differential effects of UTP, ATP, and adenosine on ciliary activity of human nasal epithelial cells

AJP Cell Physiology ◽

10.1152/ajpcell.2001.280.6.c1485 ◽

2001 ◽

Vol 280 (6) ◽

pp. C1485-C1497 ◽

Cited By ~ 86

Author(s):

Diane M. Morse ◽

Jennifer L. Smullen ◽

C. William Davis

Keyword(s):

Epithelial Cells ◽

Beat Frequency ◽

Ciliary Beat Frequency ◽

Ciliary Activity ◽

Maximal Effect ◽

Ciliary Beating ◽

Mediated Effects ◽

Human Nasal Epithelium ◽

Human Nasal Epithelial Cells ◽

Sustained Responses

The purinergic regulation of ciliary activity was studied using small, continuously superfused explants of human nasal epithelium. The P2Y2 purinoceptor (P2Y2-R) was identified as the major purinoceptor regulating ciliary beat frequency (CBF); UTP (EC50 = 4.7 μM), ATP, and adenosine-5′- O-(3-thiotriphosphate) elicited similar maximal responses, approximately twofold over baseline. ATP, however, elicited a post-peak sustained plateau in CBF (1.83 ± 0.1-fold), whereas the post-peak CBF response to UTP declined over 15 min to a low-level plateau (1.36 ± 0.16-fold). UDP also stimulated ciliary beating, probably via P2Y6-R, with a maximal effect approximately one-half that elicited by P2Y2-R stimulation. Not indicated were P2Y1-R-, P2Y4-R-, or P2Y11-R-mediated effects. A2B-receptor agonists elicited sustained responses in CBF approximately equal to those from UTP/ATP [5′-( N-ethylcarboxamido)adenosine, EC50 = 0.09 μM; adenosine, EC50 = 0.7 μM]. Surprisingly, ADP elicited a sustained stimulation in CBF. The ADP effect and the post-peak sustained portion of the ATP response in CBF were inhibited by the A2-R antagonist 8-( p-sulfophenyl)theophylline. Hence, ATP affects ciliary activity through P2Y2-R and, after an apparent ectohydrolysis to adenosine, through A2BAR.

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Ciliomotor circuitry underlying whole-body coordination of ciliary activity in the Platynereis larva

10.1101/108035 ◽

2017 ◽

Cited By ~ 1

Author(s):

Csaba Verasztó ◽

Nobuo Ueda ◽

Luis A. Bezares-Calderón ◽

Aurora Panzera ◽

Elizabeth A. Williams ◽

...

Keyword(s):

Beat Frequency ◽

Ciliary Beat Frequency ◽

Whole Body ◽

Ciliary Activity ◽

Ciliary Beating ◽

Stop And Go ◽

Multiciliated Cells ◽

Platynereis Dumerilii ◽

Catecholaminergic Cells ◽

Ciliary Locomotion

AbstractCiliated surfaces harbouring synchronously beating cilia can generate fluid flow or drive locomotion. In ciliary swimmers, ciliary beating, arrests, and changes in beat frequency are often coordinated across extended or discontinuous surfaces. To understand how such coordination is achieved, we studied the ciliated larvae of Platynereis dumerilii, a marine annelid. Platynereis larvae have segmental multiciliated cells that regularly display spontaneous coordinated ciliary arrests. We used whole-body connectomics, activity imaging, transgenesis, and neuron ablation to characterize the ciliomotor circuitry. We identified cholinergic, serotonergic, and catecholaminergic ciliomotor neurons. The synchronous rhythmic activation of cholinergic cells drives the coordinated arrests of all cilia. The serotonergic cells are active when cilia are beating. Serotonin inhibits the cholinergic rhythm, and increases ciliary beat frequency. Based on their connectivity and alternating activity, the catecholaminergic cells may generate the rhythm. The ciliomotor circuitry thus constitutes a stop-and-go pacemaker system for the whole-body coordination of ciliary locomotion.

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Effects of ethanol on in vitro ciliary motility

Journal of Applied Physiology ◽

10.1152/jappl.1988.65.4.1617 ◽

1988 ◽

Vol 65 (4) ◽

pp. 1617-1620 ◽

Cited By ~ 7

Author(s):

D. R. Maurer ◽

J. Liebman

Keyword(s):

Beat Frequency ◽

Slow Motion ◽

Ciliary Beat Frequency ◽

Blood Levels ◽

Ciliary Beating ◽

Ciliary Motility ◽

Social Drinking ◽

High Concentrations ◽

Ciliary Beat

Consumption of ethanol can impair lung function and slow total lung clearance. High concentrations of ethanol have been shown to slow or arrest ciliary beating. This study examined the effects of concentrations of alcohol comparable to blood levels achieved from social drinking on ciliary beat frequency. We obtained ciliated cells by brushing the trachea of unanesthetized sheep during fiber-optic bronchoscopy. The cells were suspended in a perfusion chamber and physiological conditions were maintained in vitro. Ciliary beat frequency and synchrony were determined by slow-motion analysis of video images obtained by interference contrast microscopy. Metachronal ciliary coordination was observed in all preparations. The ciliary beat frequency was stimulated at ethanol concentrations from 0.01 up to but not including 0.1%, unchanged at 0.5 and 1%, and slowed at 2%. While confirming inhibition of ciliary motility at very high ethanol levels, we observed no acute impairment of ciliary function at ethanol concentrations comparable to those achieved from social drinking. Indeed, we found an unexpected stimulation of ciliary beating at low levels of ethanol. How this alteration in ciliary beating would affect pulmonary clearance remains unknown at this time.

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Deep phenotyping, including quantitative ciliary beating parameters, and extensive genotyping in primary ciliary dyskinesia

Journal of Medical Genetics ◽

10.1136/jmedgenet-2019-106424 ◽

2019 ◽

Vol 57 (4) ◽

pp. 237-244 ◽

Cited By ~ 2

Author(s):

Sylvain Blanchon ◽

Marie Legendre ◽

Mathieu Bottier ◽

Aline Tamalet ◽

Guy Montantin ◽

...

Keyword(s):

Primary Ciliary Dyskinesia ◽

High Speed ◽

Genetic Disorder ◽

Beat Frequency ◽

Ciliary Beat Frequency ◽

Central Complex ◽

Ciliary Beating ◽

Recovery Stroke ◽

Biallelic Mutations ◽

Ciliary Dyskinesia

BackgroundPrimary ciliary dyskinesia (PCD) is a rare genetic disorder resulting in abnormal ciliary motility/structure, extremely heterogeneous at genetic and ultrastructural levels. We aimed, in light of extensive genotyping, to identify specific and quantitative ciliary beating anomalies, according to the ultrastructural phenotype.MethodsWe prospectively included 75 patients with PCD exhibiting the main five ultrastructural phenotypes (n=15/group), screened all corresponding PCD genes and measured quantitative beating parameters by high-speed video-microscopy (HSV).ResultsSixty-eight (91%) patients carried biallelic mutations. Combined outer/inner dynein arms (ODA/IDA) defect induces total ciliary immotility, regardless of the gene involved. ODA defect induces a residual beating with dramatically low ciliary beat frequency (CBF) related to increased recovery stroke and pause durations, especially in case of DNAI1 mutations. IDA defect with microtubular disorganisation induces a low percentage of beating cilia with decreased beating angle and, in case of CCDC39 mutations, a relatively conserved mean CBF with a high maximal CBF. Central complex defect induces nearly normal beating parameters, regardless of the gene involved, and a gyrating motion in a minority of ciliated edges, especially in case of RSPH1 mutations. PCD with normal ultrastructure exhibits heterogeneous HSV values, but mostly an increased CBF with an extremely high maximal CBF.ConclusionQuantitative HSV analysis in PCD objectives beating anomalies associated with specific ciliary ultrastructures and genotypes. It represents a promising approach to guide the molecular analyses towards the best candidate gene(s) to be analysed or to assess the pathogenicity of the numerous sequence variants identified by next-generation-sequencing.

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Low dimensional disturbance observer-based control for nonlinear parabolic PDE systems with spatio-temporal disturbances

International Journal of Robust and Nonlinear Control ◽

10.1002/rnc.3468 ◽

2015 ◽

Vol 26 (12) ◽

pp. 2686-2707 ◽

Cited By ~ 5

Author(s):

Hong-Du Wang ◽

Huai-Ning Wu ◽

Lei Guo

Keyword(s):

Disturbance Observer ◽

Nonlinear Parabolic ◽

Parabolic Pde ◽

Pde Systems ◽

Nonlinear Parabolic Pde ◽

Spatio Temporal ◽

Low Dimensional

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Pcdp1 is a central apparatus protein that binds Ca2+-calmodulin and regulates ciliary motility

The Journal of Cell Biology ◽

10.1083/jcb.200912009 ◽

2010 ◽

Vol 189 (3) ◽

pp. 601-612 ◽

Cited By ~ 64

Author(s):

Christen G. DiPetrillo ◽

Elizabeth F. Smith

Keyword(s):

Primary Ciliary Dyskinesia ◽

Calcium Concentration ◽

Beat Frequency ◽

Calcium Sensor ◽

Central Pair ◽

Ciliary Motility ◽

Significant Impairment ◽

Central Apparatus ◽

Cilia And Flagella ◽

Ciliary Dyskinesia

For all motile eukaryotic cilia and flagella, beating is regulated by changes in intraciliary calcium concentration. Although the mechanism for calcium regulation is not understood, numerous studies have shown that calmodulin (CaM) is a key axonemal calcium sensor. Using anti-CaM antibodies and Chlamydomonas reinhardtii axonemal extracts, we precipitated a complex that includes four polypeptides and that specifically interacts with CaM in high [Ca2+]. One of the complex members, FAP221, is an orthologue of mammalian Pcdp1 (primary ciliary dyskinesia protein 1). Both FAP221 and mammalian Pcdp1 specifically bind CaM in high [Ca2+]. Reduced expression of Pcdp1 complex members in C. reinhardtii results in failure of the C1d central pair projection to assemble and significant impairment of motility including uncoordinated bends, severely reduced beat frequency, and altered waveforms. These combined results reveal that the central pair Pcdp1 (FAP221) complex is essential for control of ciliary motility.

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Low-Dimensional Approximation for Control of Spatio-Temporal Processes Using Principal Interaction Patterns

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.591-593.1217 ◽

2012 ◽

Vol 591-593 ◽

pp. 1217-1220

Author(s):

Xiang Ping Cao ◽

Zhao Yang Li ◽

Mei Xing Liu

Keyword(s):

Galerkin Approximation ◽

Basis Functions ◽

Interaction Patterns ◽

Infinite Dimensional ◽

Dynamical Behaviors ◽

Dimensional Approximation ◽

Spatio Temporal ◽

Low Dimensional Approximations ◽

Low Dimensional ◽

Advanced Model

Although the first-principal models of the spatio-temporal processes can accurately predict nonlinear and distributed dynamical behaviors, their infinite-dimensional nature does not allow their directly use. In this note, low-dimensional approximations for control of spatio-temporal processes using principal interaction patterns are constructed. Advanced model reduction approach based on spatial basis function expansion together with Galerkin method is used to obtain the low-dimensional approximation. Spatial structure called principal interaction patterns are extracted from the system according to a variational principle and used as basis functions in a Galerkin approximation. The simulations of the burgers equations has illustrated that low-dimensional approximation based on principal interaction patterns for spatio-temporal processes has smaller errors than more conventional approaches using Fourier modes or Empirical Eigenfunctions as basis functions.

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Online Long-Term Object Tracking Based on Compressed Haar-Like Features via Sparse Representation

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.989-994.1610 ◽

2014 ◽

Vol 989-994 ◽

pp. 1610-1614

Author(s):

Ming Zhao ◽

Lu Ping Wang ◽

Lu Ping Zhang

Keyword(s):

Sparse Representation ◽

Target Location ◽

Model Updating ◽

Dimensional Space ◽

Reconstruction Error ◽

Illumination Changes ◽

Spatio Temporal ◽

Low Dimensional ◽

Scale Variation

Online long-term tracking is a challenging problem as data streams change over time. In this paper, sparse representation has been applied to visual tracking by finding the most correct sample with minimal reconstruction error using compressed Haar-like features. However, most sparse representation tracking algorithm introduce l1 regularization into the PCA reconstruction using samples directly, which leads to complexity computation and can not adapt to occlusion, rotation and change in size. Our model updating not only uses the samples from the training set, but also generates the warped versions (include scale variation, rotation, occlusion and illumination changes) for the previous tracking result. Also, we do not use the samples in models for sparse representation directly, but the Haar-like features instead which are compressed in a very low-dimensional space. In addition, we use a robust and fast algorithm which exploits the spatio-temporal context for predicting the target location in the next frame. This step will lead to the reduction of the searching range by the detector. We demonstrate the proposed method is able to track objects well under pose and scale variation, rotation, occlusion and illumination with great real-time performance on challenging image sequences.

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