The Thermal Dependence of Flagellar Activity in Strigomonas Oncopelti

1965 ◽  
Vol 42 (3) ◽  
pp. 537-544
Author(s):  
M. E. J. HOLWILL ◽  
N. R. SILVESTER
Keyword(s):  
Activation Enthalpy ◽  
Beat Frequency ◽  
Published Data ◽  
Activation Entropy ◽  
Present Value ◽  
Kcal Mole ◽  
Thermal Dependence ◽  
Flagellar Beat ◽  
Rate Limiting

The flagellar beat frequency of Strigomonas oncopelti was found by cinémicrophotography at temperatures in the range 4-45° C. The thermal dependence is described by an activation enthalpy (ΔH‡) of 15.4 kcal./mole and an activation entropy (ΔS‡ of -1 e.u. ΔH‡ is comparable with published data on cilia and glycerol-extracted sperm. Values of ΔS‡ (-20 e.u.) deduced from the literature suggest a rate-limiting reaction between ions of like charge although the present value does not support this idea.

scholarly journals Thermodynamic Aspects of Flagellar Activity

1967 ◽  
Vol 47 (2) ◽  
pp. 249-265
Author(s):  
M. E. J. HOLWILL ◽  
N. R. SILVESTER
Keyword(s):  
Regression Line ◽  
Smooth Muscles ◽  
Activation Entropy ◽  
Striated Muscles ◽  
Kcal Mole ◽  
Thermal Dependence ◽  
Activation Free Energy ◽  
The Common ◽  
Cilia And Flagella ◽  
Rate Limiting

1. The frequencies of the beat of cilia and flagella from various organisms have been determined at temperatures in the range 5-35°C. 2. Values of the activation enthalpy (ΔH‡, kcal./mole) and activation entropy (ΔS‡, e.u.) derived from the thermal dependence of frequency show a linear correlation of the form, ΔS‡ = 3·25 ΔH‡-50·75. 3. The corresponding isokinetic activation free energy is 15·6 kcal./mole. 4. The results support a hypothesis that the breakdown of an ATP-ATPase complex could be the common rate-limiting reaction for flagellar activity. 5. Values of ΔH‡ and ΔS‡ for the decay of length or tension in striated muscles also fall on the same regression line but some smooth muscles show deviations.

The kinetics of the thermal insertion reaction of tin(II) halides with cyclopentadienyliron dicarbonyl dimer

1970 ◽  
Vol 48 (21) ◽  
pp. 3300-3303 ◽  
Author(s):  
P. F. Barrett ◽  
Kenneth K. W. Sun
Keyword(s):  
Activation Energy ◽  
Kinetic Data ◽  
Activation Enthalpy ◽  
Visible Spectrum ◽  
Nucleophilic Attack ◽  
Insertion Reaction ◽  
Activation Entropy ◽  
Kcal Mole ◽  
Metal Metal ◽  
Kinetics Of

The kinetics of the thermal insertion reaction of SnBr2 and SnCl2 with the metal–metal bonded dimer [π-C5H3Fe(CO)2]2 have been studied by following the change in the visible spectrum. The kinetic data are consistent with a two-stage mechanism involving the formation of a carbonyl-bridged intermediate followed by nucleophilic attack by the halides on this intermediate. The formation of the intermediate requires an activation enthalpy of 38.0 ± 1.0 kcal/mole, and an activation entropy of 45.5 + 1.5 cal mole−1 deg−1. The activation energy required to break the Fe—Fe bond is estimated to be about 32 kcal/mole.

scholarly journals Rapid sperm capture: High-throughput flagellar waveform analysis

2019 ◽  
Author(s):  
M.T. Gallagher ◽  
G. Cupples ◽  
E.H. Ooi ◽  
J.C. Kirkman-Brown ◽  
D.J. Smith
Keyword(s):  
Beat Frequency ◽  
Surrounding Medium ◽  
Human Sperm ◽  
Large Cell ◽  
Waveform Analysis ◽  
Mechanical Activity ◽  
Natural Fertility ◽  
Published Data ◽  
Waveform Data ◽  
Flagellar Beat

SummaryFlagella are critical across all eukaryotic life, and the human sperm flagellum is crucial to natural fertility. Existing automated sperm diagnostics (CASA) rely on tracking the sperm head and extrapolating measures. We describe fully-automated tracking and analysis of flagellar movement for large cell numbers. The analysis is demonstrated on freely-motile cells in low and high viscosity fluids, and validated on published data of tethered cells undergoing pharmacological hyperactivation. Direct analysis of the flagellar beat reveals that the CASA measure ‘beat cross frequency’, does not measure beat frequency. A new measurement, track centroid speed, is validated as an accurate differentiator of progressive motility. Coupled with fluid mechanics codes, waveform data enables extraction of experimentally intractable quantities such as energy dissipation, disturbance of the surrounding medium and viscous stresses. We provide a powerful and accessible research tool, enabling connection of the cell’s mechanical activity to its motility and effect on its environment.

Temperature effects on anaphase chromosome movement in the spermatocytes of two species of crane flies (Nephrotoma suturalis Loew and Nephrotoma ferruginea Fabricius)

1979 ◽  
Vol 39 (1) ◽  
pp. 29-52
Author(s):  
C.J. Schaap ◽  
A. Forer
Keyword(s):  
Sex Chromosomes ◽  
Temperature Effects ◽  
Sex Chromosome ◽  
Beat Frequency ◽  
General Pattern ◽  
Force Production ◽  
Temperature Shift ◽  
Ciliary Beat Frequency ◽  
Chromosome Movement ◽  
Flagellar Beat

Using phase-contrast cinemicrography on living crane fly (Nephrotoma suturalis Loew and Nephrotoma ferruginea Fabricius) spermatocytes, we have studied the effects of a range of temperatures (6–30 degrees C) on the anaphase I chromosome-to-pole movements of both autosomes and sex chromosomes. In contrast to previous work we have been able to study chromosome-to-pole velocities of autosomes without concurrent pole-to-pole elongation. In these cells we found that the higher the temperature, the faster was the autosomal chromosomes movement. From reviewing the literature we find that the general pattern of the effects of temperature on chromosome movement is similar whether or not pole-to-pole elongation occurs simultaneously with the chromosome-to-pole movement. Changes in cellular viscosities calculated from measurements of particulate Brownian movement do not seem to be able to account for the observed velocity differences due to temperature. Temperature effects on muscle contraction speed, flagellar beat frequency, ciliary beat frequency, granule flow in nerves, and chromosome movement have been compared, as have the activation energies for the rate-limiting steps in these motile systems: no distinction between possible mechanisms of force production is possible using these comparisons. The data show that even the different autosomes within single spermatocytes usually move at different speeds. These velocity differences cannot simply be related to chromosome size as the autosomes are visually indistinguishable. The sex chromosomes start their anaphase poleward movement after that of the autosomes, and move more slowly (by a factor of about 4), but their velocities appear to be affected by temperature in the same fashion as those of the autosomes. The interval between the onset of autosome anaphase and sex chromosome anaphase is also affected by temperature: the higher the temperature, the shorter the interval between the 2 stages. We have observed abnormalities in sex chromosome segregation, which may be due to temperature, but have not determined what the exact temperature shift conditions are that cause these abnormalities.

scholarly journals Effect of beat frequency on the velocity of microtubule sliding in reactivated sea urchin sperm flagella under imposed head vibration.

1995 ◽  
Vol 198 (3) ◽  
pp. 645-653 ◽  
Author(s):  
C Shingyoji ◽  
K Yoshimura ◽  
D Eshel ◽  
K Takahashi ◽  
I R Gibbons
Keyword(s):  
Sea Urchin ◽  
Vibration Frequency ◽  
Beat Frequency ◽  
Distal Region ◽  
Bend Angle ◽  
Vibration Frequencies ◽  
Sliding Velocity ◽  
Flagellar Beat ◽  
Tripneustes Gratilla ◽  
Sea Urchin Sperm

The heads of demembranated spermatozoa of the sea urchin Tripneustes gratilla, reactivated at different concentrations of ATP, were held by suction in the tip of a micropipette and vibrated laterally with respect to the head axis. This imposed vibration resulted in a stable rhythmic beating of the reactivated flagella that was synchronized to the frequency of the micropipette. The reactivated flagella, which in the absence of imposed vibration had an average beat frequency of 39 Hz at 2 mmol l-1 ATP, showed stable beating synchronized to the pipette vibration over a range of 20-70 Hz. Vibration frequencies above 70 Hz caused irregular, asymmetrical beating, while those below 20 Hz induced instability of the beat plane. At ATP concentrations of 10-100 mumol l-1, the range of vibration frequency capable of maintaining stable beating was diminished; an increase in ATP concentration above 2 mmol l-1 had no effect on the range of stable beating. In flagella reactivated at ATP concentrations above 100 mumol l-1, the apparent time-averaged sliding velocity of axonemal microtubules decreased when the imposed frequency was below the undriven flagellar beat frequency, but at higher imposed frequencies it remained constant, with the higher frequency being accompanied by a decrease in bend angle. This maximal sliding velocity at 2 mmol l-1 ATP was close to the sliding velocity in the distal region of live spermatozoa, possibly indicating that it represents an inherent limit in the velocity of active sliding.(ABSTRACT TRUNCATED AT 250 WORDS)

Kinetic Studies on the Polymerization of Dicyclohexylmethylmethane-4,4'-Diisocyanate with Polyoxytetramethylene Diol

2013 ◽  
Vol 791-793 ◽  
pp. 32-35
Author(s):  
Jian Cheng Wang
Keyword(s):  
Rate Constant ◽  
Arrhenius Equation ◽  
Activation Enthalpy ◽  
Kinetic Studies ◽  
Activation Entropy ◽  
Dimethyl Acetamide ◽  
Different Temperatures ◽  
Ft Ir ◽  
Temperature Activation

Dicyclohexylmethylmethane-4,4'-diisocyanate is used to react with polyoxytetramethylene diol at different temperatures. N,N-Dimethyl acetamide is used as solvent.In situFT-IR is used to monitor the reaction to work out rate constant, Arrhenius equation and Eyring equation. The polymerization has been found to be a second order reaction, and the rate constant increases with the rise of temperature. Activation energy (Ea), activation enthalpy (ΔH) and activation entropy (ΔS) for the polymerization are respectively calculated out, which are very useful to reveal the reaction mechanism.

Assembly and function of Chlamydomonas flagellar mastigonemes as probed with a monoclonal antibody

1996 ◽  
Vol 109 (1) ◽  
pp. 57-62 ◽  
Author(s):  
S. Nakamura ◽  
G. Tanaka ◽  
T. Maeda ◽  
R. Kamiya ◽  
T. Matsunaga ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Beat Frequency ◽  
Distal Portion ◽  
Distal Region ◽  
Ring Structure ◽  
Live Cells ◽  
Swimming Velocity ◽  
Flagellar Beat ◽  
Original Length ◽  
And Function

Mastigonemes are hair-like projections on the flagella of various kinds of lower eukaryotes. We obtained a monoclonal antibody (mAb-MAST1) to mastigonemes of Chlamydomonas reinhardtii, and found that it reacts with a single flagellar glycoprotein of about 230 kDa. Interestingly, immunofluorescence microscopy demonstrated that mAb-MAST1 recognizes not only the flagellar mastigonemes but also a ring composed of 10 or more particles located in the anterior end of the cell body close to the flagellar bases. The ring structure may be the pool of the mastigoneme protein. When the flagella are amputated, they regenerate to their original length in 90–120 minutes. We found that mastigonemes appear on the new flagellar surface as early as 15 minutes after deflagellation, and that new mastigonemes are mostly assembled onto the distal region of the flagellar surface. Mastigonemes thus appear to be inserted into the membrane only in the distal region of the flagellum. Alternatively, mastigonemes may be inserted at the base and transported very rapidly to the distal portion where they are trapped. When live cells are treated with mAb-MAST1, mastigonemes disappear from the flagellar surface. In these mAb-MAST1 treated cells, the swimming velocity decreases to 70–80% of the normal value, although the flagellar beat frequency increases to approximately 110% of the control. These findings demonstrate vectorial transport of mastigonemes to their assembly sites, and show that mastigonemes function to increase flagellar propulsive force by increasing the effective surface of the flagellum.

scholarly journals IC138 Is a WD-Repeat Dynein Intermediate Chain Required for Light Chain Assembly and Regulation of Flagellar Bending

2004 ◽  
Vol 15 (12) ◽  
pp. 5431-5442 ◽  
Author(s):  
Triscia W. Hendrickson ◽  
Catherine A. Perrone ◽  
Paul Griffin ◽  
Kristin Wuichet ◽  
Joshua Mueller ◽  
...  
Keyword(s):  
Light Chain ◽  
Beat Frequency ◽  
Wild Type ◽  
Central Pair ◽  
Flagellar Beat ◽  
C Terminus ◽  
Dynein Intermediate Chain ◽  
Radial Spokes ◽  
Calculated Mass ◽  
Wd Repeat

Increased phosphorylation of dynein IC IC138 correlates with decreases in flagellar microtubule sliding and phototaxis defects. To test the hypothesis that regulation of IC138 phosphorylation controls flagellar bending, we cloned the IC138 gene. IC138 encodes a novel protein with a calculated mass of 111 kDa and is predicted to form seven WD-repeats at the C terminus. IC138 maps near the BOP5 locus, and bop5-1 contains a point mutation resulting in a truncated IC138 lacking the C terminus, including the seventh WD-repeat. bop5-1 cells display wild-type flagellar beat frequency but swim slower than wild-type cells, suggesting that bop5-1 is altered in its ability to control flagellar waveform. Swimming speed is rescued in bop5-1 transformants containing the wild-type IC138, confirming that BOP5 encodes IC138. With the exception of the roadblock-related light chain, LC7b, all the other known components of the I1 complex, including the truncated IC138, are assembled in bop5-1 axonemes. Thus, the bop5-1 motility phenotype reveals a role for IC138 and LC7b in the control of flagellar bending. IC138 is hyperphosphorylated in paralyzed flagellar mutants lacking radial spoke and central pair components, further indicating a role for the radial spokes and central pair apparatus in control of IC138 phosphorylation and regulation of flagellar waveform.

scholarly journals Extragenic suppressors of paralyzed flagellar mutations in Chlamydomonas reinhardtii identify loci that alter the inner dynein arms.

1992 ◽  
Vol 118 (5) ◽  
pp. 1163-1176 ◽  
Author(s):  
M E Porter ◽  
J Power ◽  
S K Dutcher
Keyword(s):  
Chlamydomonas Reinhardtii ◽  
Synergistic Effects ◽  
Beat Frequency ◽  
Suppressor Mutation ◽  
Swimming Velocity ◽  
Temperature Sensitive ◽  
Restrictive Temperature ◽  
Wild Type ◽  
Flagellar Beat ◽  
Extragenic Suppressors

We have analyzed extragenic suppressors of paralyzed flagella mutations in Chlamydomonas reinhardtii in an effort to identify new dynein mutations. A temperature-sensitive allele of the PF16 locus was mutagenized and then screened for revertants that could swim at the restrictive temperature (Dutcher et al. 1984. J. Cell Biol. 98:229-236). In backcrosses of one of the revertant strains to wild-type, we recovered both the original pf16 mutation and a second, unlinked suppressor mutation with its own flagellar phenotype. This mutation has been identified by both recombination and complementation tests as a new allele of the previously uncharacterized PF9 locus on linkage group XII/XIII. SDS-PAGE analysis of isolated flagellar axonemes and dynein extracts has demonstrated that the pf9 strains are missing four polypeptides that form the I1 inner arm dynein subunit. The primary effect of the loss of the I1 subunit is a decrease in the forward swimming velocity due to a change in the flagellar waveform. Both the flagellar beat frequency and the axonemal ATPase activity are nearly wild-type. Examination of axonemes by thin section electron microscopy and image averaging methods reveals that a specific domain of the inner arm complex is missing in the pf9 mutant strains (see accompanying paper by Mastronarde et al.). When combined with other flagellar defects, the loss of the I1 subunit has synergistic effects on both flagellar assembly and flagellar motility. These synthetic phenotypes provide a screen for new suppressor mutations in other loci. Using this approach, we have identified the first interactive suppressors of a dynein arm mutation and an unusual bypass suppressor mutation.

scholarly journals Time-reversal symmetric component of the flagellar beat enhances the translational and rotational velocities of isolated Chlamydomonas flagella

2021 ◽  
Author(s):  
Azam Gholami ◽  
Raheel Ahmad ◽  
Albert J Bae ◽  
Alain Pumir ◽  
Eberhard Bodenschatz
Keyword(s):  
Beat Frequency ◽  
Fluid Flows ◽  
Symmetric Mode ◽  
Wave Component ◽  
Intrinsic Curvature ◽  
Flagellar Beat ◽  
Cilia And Flagella ◽  
Micro Organisms ◽  
Insight Into ◽  
Dynamic Wave

The beating of cilia and flagella is essential to perform many important biological functions, including generating fluid flows on the cell surface or propulsion of micro-organisms. In this work, we analyze the motion of isolated and demembranated flagella from green algae Chlamydomonas reinhardtii, which act as ATP-driven micro-swimmers. The waveform of the Chlamydomonas beating flagella has an asymmetric waveform that is known to involve the superposition of a static component, corresponding to a fixed, intrinsic curvature, and a dynamic wave component traveling in the base-to-tip direction at the fundamental beat frequency, plus higher harmonics. Here, we demonstrate that these modes are not sufficient to reproduce the observed flagella waveforms. We find that two extra modes play an essential role to describe the motion: first, a time-symmetric mode, which corresponds to a global oscillation of the axonemal curvature, and second, a secondary tip-to-base wave component at the fundamental frequency that propagates opposite to the dominant base-to-tip wave, albeit with a smaller amplitude. Although the time-symmetric mode cannot, by itself, contribute to propulsion (scallop theorem), it does enhance the translational and rotational velocities of the flagellum by approximately a factor of 2. This mode highlights a long-range coupled on/off activity of force-generating dynein motors and can provide further insight into the underling biology of the ciliary beat.

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