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Studies on the eel sperm flagellum. 3. Vibratile motility and rotatory bending
1Department of Physiology, School of Medical Sciences, University of Bristol, UK.
Cell Motility and the Cytoskeleton
|March 31, 1998
Summary
Sperm flagella can exhibit vibratile motion for propulsion when normal motility is inactive. Mechanical stimulation of the axoneme, with the sperm head present, can restore normal motility.
Area of Science:
- Cell Biology
- Biophysics
- Sperm Motility
Background:
- Flagella are crucial for sperm motility, typically exhibiting a 9+2 axoneme structure.
- Inner dynein arms are key components powering flagellar movement.
Purpose of the Study:
- To investigate alternative motility mechanisms in flagella powered solely by inner dynein arms.
- To understand the role of the sperm head in regulating flagellar motility.
Main Methods:
- Observation of flagellar motion under varying conditions (e.g., with/without sperm head).
- Mechanical stimulation to assess motility responses.
- Stroboscopic analysis (limited by speed).
Main Results:
- Flagella can exhibit slow forward propulsion via rapid, low-amplitude vibratile motion when normal motility is absent.
- The sperm head is essential for maintaining the fluid-mechanical interactions that sustain normal motility.
- Mechanical stimulation can trigger a return to normal motility, indicating a deformation threshold.
- Some flagella without sperm heads display slow, clockwise basal bending, possibly a restricted form of normal motility.
Conclusions:
- Flagellar motility is complex, with backup mechanisms like vibratile motion.
- Sperm head interaction is critical for sustained, normal flagellar function.
- Axonemal deformation is a key trigger for initiating and maintaining motility.