Abstract
Spermatozoa of the sea urchin, Hemicentrotus pulcherrimus, were demembranated with solutions containing various detergents and then reactivated with ATP. The reactivation rates of sperm demembranated with 0.05% (w/v) saponin, Brij 58, or CHAPS (3-[(3-cholamidopropyl) dimethylam-monio]-1-propanesulfonate) were less than 10%; increasing the concentration of detergent up to 0.1% (w/v) did not improve the reactivation rate. High reac-tivation rates were obtained with 0.04% (w/v) Triton X-100, 0.05% Nonidet P-40, 0.04% CHAPS + 0.01% Triton X-100, or 0.04% CHAPS +0.01% Nonidet P-40. The flagellar waveform as well as the relationship between the beat frequency and the ATP concentration did not vary among these four preparations. Unlike the live sperm, Triton-extracted sperm failed to undergo rotation of the flagellar beat plane for more than one and a half revolutions when lateral vibration was imposed on the head in a plane that rotated around the head axis. However, the sperm demembranated with a solution containing 0.04% CHAPS and 0.01% Nonidet P-40 responded to the imposed rotatory vibration by rotating their flagellar beat plane through more than 10 cycles. Elec-tron microscopic studies showed that the membrane were completely removed from around the axoneme by treatment with Triton X-100 or CHAPS + Nonidet P-40. These results indicate that the rotation of the beat plane does not require the presence of the plasma membrane, and also that the mechanism con-trolling the beat plane is independent of that controlling other parameters of flagellar movement.
