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Direct measurements of microtubule sliding in the flagella of actively swimming, demembranated, spermatozoa have been made using submicron diameter gold beads as markers on the exposed outer doublet microtubules. With spermatozoa of the tunicate, Ciona, these measurements confirm values of sliding calculated indirectly by measuring angles relative to the axis of the sperm head. Both methods of measurement show a nonuniform amplitude of oscillatory sliding along the length of the flagellum, providing direct evidence that "oscillatory synchronous sliding" can be occurring in the flagellum, in addition to the metachronous sliding that is necessary to propagate a bending wave. Propagation of constant amplitude bends is not accomplished by propagation of a wave of oscillatory sliding of constant amplitude, and therefore appears to require a mechanism for monitoring and controlling the bend angle as bends propagate. With sea urchin spermatozoa, the direct measurements of sliding do not agree with the values calculated by measuring angles relative to the head axis. The oscillation in angular orientation of the sea urchin sperm head as it swims appears to be accommodated by flexure at the head-flagellum junction and does not correspond to oscillation in orientation of the basal end of the flagellum. Consequently, indirect calculations of sliding based on angles measured relative to the longitudinal axis of the sperm head can be seriously inaccurate in this species.
Brokaw,
Bend propagation by a sliding filament model for flagella.
1971, Pubmed
Brokaw,
Bend propagation by a sliding filament model for flagella.
1971,
Pubmed
Brokaw,
Mechanochemical coupling in flagella. II. Effects of viscosity and thiourea on metabolism and motility of Ciona spermatozoa.
1968,
Pubmed
Brokaw,
Computerized analysis of flagellar motility by digitization and fitting of film images with straight segments of equal length.
1990,
Pubmed
,
Echinobase
Brokaw,
Modulation of the asymmetry of sea urchin sperm flagellar bending by calmodulin.
1985,
Pubmed
,
Echinobase
Brokaw,
Calcium-induced asymmetrical beating of triton-demembranated sea urchin sperm flagella.
1979,
Pubmed
,
Echinobase
Brokaw,
Sperm motility.
1986,
Pubmed
,
Echinobase
Brokaw,
A lithium-sensitive regulator of sperm flagellar oscillation is activated by cAMP-dependent phosphorylation.
1987,
Pubmed
,
Echinobase
Eshel,
Determination of the average shape of flagellar bends: a gradient curvature model.
1988,
Pubmed
,
Echinobase
Eshel,
New evidence for a "biased baseline" mechanism for calcium-regulated asymmetry of flagellar bending.
1987,
Pubmed
,
Echinobase
Gibbons,
Transient flagellar waveforms in reactivated sea urchin sperm.
1986,
Pubmed
,
Echinobase
Gibbons,
Sliding and bending in sea urchin sperm flagella.
1982,
Pubmed
,
Echinobase
Gibbons,
Transient flagellar waveforms during intermittent swimming in sea urchin sperm. II. Analysis of tubule sliding.
1981,
Pubmed
,
Echinobase
Goldstein,
Motility of basal fragments of sea urchin sperm flagella.
1981,
Pubmed
,
Echinobase
Goldstein,
Form of developing bends in reactivated sperm flagella.
1976,
Pubmed
,
Echinobase
Goldstein,
Asymmetric waveforms in echinoderm sperm flagella.
1977,
Pubmed
,
Echinobase
Omoto,
Structure and behaviour of the sperm terminal filament.
1982,
Pubmed
,
Echinobase
Sale,
The axonemal axis and Ca2+-induced asymmetry of active microtubule sliding in sea urchin sperm tails.
1986,
Pubmed
,
Echinobase
Satir,
Studies on cilia. 3. Further studies on the cilium tip and a "sliding filament" model of ciliary motility.
1968,
Pubmed
Shingyoji,
Effect of imposed head vibration on the stability and waveform of flagellar beating in sea urchin spermatozoa.
1991,
Pubmed
,
Echinobase
Silvester,
An analysis of hypothetical flagellar waveforms.
1972,
Pubmed
Warner,
The structural basis of ciliary bend formation. Radial spoke positional changes accompanying microtubule sliding.
1974,
Pubmed
