scholarly journals Effects of detergents used to demembranate the sea-urchin spermatozoa on the reactivated flagellar movement, with special reference to the rotatability of the plane of flagellar beat.

1989 ◽  
Vol 14 (6) ◽  
pp. 751-758
Author(s):  
Jun Katada ◽  
Chikako Shingyoji ◽  
Keiichi Takahashi
Keyword(s):  
Special Reference ◽  
Sea Urchin ◽  
Flagellar Beat

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)

The polyglutamylated lateral chain of alpha-tubulin plays a key role in flagellar motility

1996 ◽  
Vol 109 (6) ◽  
pp. 1545-1553 ◽  
Author(s):  
C. Gagnon ◽  
D. White ◽  
J. Cosson ◽  
P. Huitorel ◽  
B. Edde ◽  
...  
Keyword(s):  
Sea Urchin ◽  
Beat Frequency ◽  
Cortical Microtubule ◽  
Flagellar Motility ◽  
Microtubule Network ◽  
Alpha Tubulin ◽  
Oxyrrhis Marina ◽  
Terminal Domain ◽  
Flagellar Beat ◽  
Sea Urchin Sperm

To investigate whether a specific isotype of tubulin is involved in flagellar motility, we have developed and screened a panel of monoclonal antibodies (mAb) generated against sea urchin sperm axonemal proteins. Antibodies were selected for their ability to block the motility of permeabilized sperm models. The antitubulin mAb B3 completely inhibited, at low concentrations, the flagellar motility of permeabilized sperm models from four sea urchin species. On immunoblots, B3 recognized predominantly alpha-tubulin in sea urchin sperm axonemes and equally well brain alpha- and beta-tubulins. Subtilisin cleavage of tubulin removed the B3 epitope, indicating that it was restricted to the last 13 amino acid residues of the C-terminal domain of alpha-tubulin. In enzyme-linked immunosorbant assays, B3 reacted with glutamylated alpha-tubulin peptides from sea urchin or mouse brain but did not bind to the unmodified corresponding peptide, indicating that it recognized polyglutamylated motifs in the C-terminal domain of alpha-tubulin. On the other hand, other tubulin antibodies directed against various epitopes of the C-terminal domain, with the exception of the antipolyglutamylated mAb GT335, had no effect on motility while having binding properties similar to that of B3. B3 and GT335 acted by decreasing the beating amplitude without affecting the flagellar beat frequency. B3 and GT335 were also capable of inhibiting the motility of flagella of Oxyrrhis marina, a 400,000,000 year old species of dinoflagellate, and those of human sperm models. Localization of the antigens recognized by B3 and GT335 by immunofluorescence techniques revealed their presence along the whole axoneme of sea urchin spermatozoa and flagella of O. marina, except for the distal tip and the cortical microtubule network of the dinoflagellate. Taken together, the data reported here indicate that the polyglutamylated lateral chain of alpha-tubulin plays a dynamic role in a dynein-based motility process.

The Effect of Partial Extraction of Dynein Arms on the Movement of Reactivated Sea-Urchin Sperm

1973 ◽  
Vol 13 (2) ◽  
pp. 337-357 ◽  
Author(s):  
BARBARA H. GIBBONS ◽  
I. R. GIBBONS
Keyword(s):  
Sea Urchin ◽  
Room Temperature ◽  
Beat Frequency ◽  
Wave Form ◽  
Bending Waves ◽  
Flagellar Beat ◽  
Elastic Forces ◽  
Dynein Arms ◽  
Triton X ◽  
Sea Urchin Sperm

Sea-urchin sperm were extracted with o.5 M KCl for 45 s at room temperature in the presence of Triton X-100, and then transferred to reactivating solution containing 1 mM ATP. The flagellar beat frequency of these KCl-extracted sperm (16 beats/s) was only about half that of control Triton-extracted sperm that had not been exposed to 0.5 M KCl (31 beats/s), although the form of their bending waves was not significantly altered. Examination by electron microscopy showed that the extraction with 0.5 M KCl removed the majority of the outer arms from the doublet tubules, leaving the inner arms apparently intact. By varying the duration of the KCl-extraction, it was shown that the rate of decrease in beat frequency paralleled the rate of disappearance of the arms. Prolonging the extraction time beyond 45 s at room temperature, or 4 min at o °C, had little further effect on beat frequency. ATPase measurements suggested that 6o-65% of the dynein in the original axonemes had been solubilized when the extraction with KCl was permitted to go to completion. These results indicate that the generation and propagation of flagellar bending waves of essentially typical form are not prevented by the removal of the outer row of dynein arms from the doublet tubules. In terms of the sliding filament model of flagellar bending, the results suggest that the rate of sliding between tubules under these conditions is proportional to the number of dynein arms present. The lack of significant change in wave form implies that the total amount of sliding that occurs during each bending cycle is not affected by the reduced number of dynein arms, but is regulated independently in some manner by the elastic forces generated by other structures in the bent axoneme.

Polarity in spontaneous unwinding after prior rotation of the flagellar beat plane in sea-urchin spermatozoa

1991 ◽  
Vol 98 (2) ◽  
pp. 183-189 ◽  
Author(s):  
K. Takahashi ◽  
C. Shingyoji ◽  
J. Katada ◽  
D. Eshel ◽  
I.R. Gibbons
Keyword(s):  
Angular Velocity ◽  
Sea Urchin ◽  
Initial Velocity ◽  
Central Pair ◽  
Counterclockwise Direction ◽  
Flagellar Beat ◽  
Elastic Distortion ◽  
The Difference ◽  
Sea Urchin Sperm

The flagellar beat plane of live and reactivated sea-urchin sperm held by their heads in the tip of a vibrating micropipette will rotate along with the plane of the imposed vibration for up to 10 revolutions in either a clockwise or a counterclockwise direction. Subsequent cessation of the imposed vibration is followed by spontaneous unwinding of the flagellar beat plane. Nearly complete unwinding occurs after prior counterclockwise winding. The unwinding of the beat plane after prior clockwise winding is incomplete, but the number of revolutions that remain unwound affects the response of the flagellar beat plane to a second set of imposed revolutions. The initial angular velocity of spontaneous unwinding is approximately proportional to the number of prior winding cycles, independent of their direction. The maximum initial velocity of unwinding was 27 rad s-1 and 20 rad s-1 for live and reactivated sperm, respectively. These data suggest that the force responsible for unwinding of the beat plane is derived from the elastic distortion of some component in the axonemal structure. The difference in completeness of spontaneous unwinding between the two directions of rotation is consistent with the previously suggested hypothesis that imposed rotation of the beat plane reflects the forced rotation of the central pair within the axoneme.

Rotating the plane of imposed vibration can rotate the plane of flagellar beating in sea-urchin sperm without twisting the axoneme

1991 ◽  
Vol 98 (2) ◽  
pp. 175-181 ◽  
Author(s):  
C. Shingyoji ◽  
J. Katada ◽  
K. Takahashi ◽  
I.R. Gibbons
Keyword(s):  
Detailed Analysis ◽  
Sea Urchin ◽  
Regulatory Structure ◽  
Polystyrene Beads ◽  
Bending Waves ◽  
Flagellar Beat ◽  
Vibration Rotation ◽  
Sea Urchin Sperm

When the head of a sea-urchin sperm is held in the tip of a micropipette and vibrated laterally, the flagellum beats in phase with the imposed vibration. Rotation of the plane of pipette vibration around the head axis induces a corresponding rotation of the plane of beating, in both live and reactivated sperm. Detailed analysis of the waveforms occurring at different stages of this rotation shows that the characteristic asymmetry of the flagellar bending waves rotates along with the plane of beat. The positions of small polystyrene beads attached as markers on the axonemes of demembranated sperm flagella appear unaffected by the rotation of the beat plane and asymmetry. The imposed rotation of the waveform is thus the result of a rotation of the coordinated pattern of sliding among the doublet tubules of the axoneme, and is not accompanied by a twisting of the whole axonemal structure. These data indicate that neither the plane of flagellar beat nor the direction of beat asymmetry is tightly dependent upon a structural or chemical specialization of particular members of the nine outer doublet microtubules, but that both are the result of some regulatory structure that can be forced to rotate relative to the outer structure of the axoneme.

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