Flexural Rigidity of Echinoderm Sperm Flagella
キーワード:
beating plane,
doublet microtubules,
dynein cross-bridge,
flagellar axoneme,
stiffness,
viscous resistance
1994 年 19 巻 6 号 p. 349-362
詳細
1994 年 19 巻 6 号 p. 349-362
The stiffness (flexural rigidity) of live sperm flagella, Triton-demembranated flagella (axonernes), trypsin-digested axonemes, and doublet microtubules of the axonemes in echinoderms was determined from the relationship between their deformation when a stream of medium was applied and the viscous resistance of the medium acting on the flagellum. The stiffness of the flagellum beating in seawater was 5.8×10-21 Nm2 for bending in the direction perpendicular to the beating plane and 4.2×10-22 Nm2 for bending within the beating plane. A similar difference in stiffness from the difference in bending directions was found in reactivated flagella with 1 Mm ATP. The stiffness of live flagella immobilized in CO2-saturated seawater and axonemes in ATP-free medium was similar to that of beating flagella for bending in the direction perpendicular to the beating plane. The stiffness of motionless flagella significantly decreased with erythro-9-(2-hydroxy-3-nonyl) adenine (EHNA) and vanadate. The trypsin-digestion of motionless axonemes did not change their stiffness. The stiffness of doublet microtubules was 1.4 ×10-23 Nm2 in 0.1 mM ATP medium and 6.1×10-23 Nm2 in ATP-free medium. These results suggest that doublet pairs lying parallel to the beating plane of the flagellum retain fewer cross-bridges than doublet pairs lying perpendicular to the beating palne.
