| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
Department of Biological Sciences, Oakland University, Rochester, Michigan
Correspondence: Address reprint requests to Charles B. Lindemann, Dept. of Biological Sciences, Oakland University, Rochester, MI 48309-4476. Tel.: 248-370-3576; E-mail: lindeman{at}oakland.edu.
In the axoneme of eukaryotic flagella the dynein motor proteins form crossbridges between the outer doublet microtubules. These motor proteins generate force that accumulates as linear tension, or compression, on the doublets. When tension or compression is present on a curved microtubule, a force per unit length develops in the plane of bending and is transverse to the long axis of the microtubule. This transverse force (t-force) is evaluated here using available experimental evidence from sea urchin sperm and bull sperm. At or near the switch point for beat reversal, the t-force is in the range of 0.25–1.0 nN/µm, with 0.5 nN/µm the most likely value. This is the case in both beating and arrested bull sperm and in beating sea urchin sperm. The total force that can be generated (or resisted) by all the dyneins on one micron of outer doublet is also 
0.5 nN. The equivalence of the maximum dynein force/µm and t-force/µm at the switch point may have important consequences. Firstly, the t-force acting on the doublets near the switch point of the flagellar beat is sufficiently strong that it could terminate the action of the dyneins directly by strongly favoring the detached state and precipitating a cascade of detachment from the adjacent doublet. Secondly, after dynein release occurs, the radial spokes and central-pair apparatus are the structures that must carry the t-force. The spokes attached to the central-pair projections will bear most of the load. The central-pair projections are well-positioned for this role, and they are suitably configured to regulate the amount of axoneme distortion that occurs during switching. However, to fulfill this role without preventing flagellar bend formation, moveable attachments that behave like processive motor proteins must mediate the attachment between the spoke heads and the central-pair structure.
This article has been cited by other articles:
 |
|
 |
|
  K. A. Lesich, D. W. Pelle, and C. B. Lindemann Insights into the Mechanism of ADP Action on Flagellar Motility Derived from Studies on Bull Sperm Biophys. J., July 1, 2008; 95(1): 472 - 482. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D. Zuccarello, A. Ferlin, A. Garolla, M. A. Pati, A. Moretti, C. Cazzadore, S. Francavilla, and C. Foresta A possible association of a human tektin-t gene mutation (A229V) with isolated non-syndromic asthenozoospermia: Case Report Hum. Reprod., April 1, 2008; 23(4): 996 - 1001. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. Weihs, T. G. Mason, and M. A. Teitell Bio-Microrheology: A Frontier in Microrheology Biophys. J., December 1, 2006; 91(11): 4296 - 4305. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 Z. Zhang, I. Kostetskii, W. Tang, L. Haig-Ladewig, R. Sapiro, Z. Wei, A. M. Patel, J. Bennett, G. L. Gerton, S. B. Moss, et al. Deficiency of SPAG16L Causes Male Infertility Associated with Impaired Sperm Motility Biol Reprod, April 1, 2006; 74(4): 751 - 759. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Kinukawa, J. Ohmuro, S. A. Baba, S. Murashige, M. Okuno, M. Nagata, and F. Aoki Analysis of Flagellar Bending in Hamster Spermatozoa: Characterization of an Effective Stroke Biol Reprod, December 1, 2005; 73(6): 1269 - 1274. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Aoyama and R. Kamiya Cyclical Interactions between Two Outer Doublet Microtubules in Split Flagellar Axonemes Biophys. J., November 1, 2005; 89(5): 3261 - 3268. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D. White, S. Aghigh, I. Magder, J. Cosson, P. Huitorel, and C. Gagnon Two Anti-radial Spoke Monoclonal Antibodies Inhibit Chlamydomonas Axonemal Motility by Different Mechanisms J. Biol. Chem., April 15, 2005; 280(15): 14803 - 14810. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. Yang, M. M. Compton, and P. Yang Dimeric Novel HSP40 Is Incorporated into the Radial Spoke Complex during the Assembly Process in Flagella Mol. Biol. Cell, February 1, 2005; 16(2): 637 - 648. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. J. Wargo, M. A. McPeek, and E. F. Smith Analysis of microtubule sliding patterns in Chlamydomonas flagellar axonemes reveals dynein activity on specific doublet microtubules J. Cell Sci., May 15, 2004; 117(12): 2533 - 2544. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. M. Sakakibara, Y. Kunioka, T. Yamada, and S. Kamimura Diameter Oscillation of Axonemes in Sea-Urchin Sperm Flagella Biophys. J., January 1, 2004; 86(1): 346 - 352. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
