JEB desktop wallpaper calendar 2016

JEB desktop wallpaper calendar 2016

Maintenance of Constant Wave Parameters by Sperm Flagella at Reduced Frequencies of Beat
C. J. BROKAW, R. JOSSLIN

Summary

1. Treatment of Ciona spermatozoa with low concentrations of Triton X-100 (less than 0·01 %) causes them to beat at lower than normal frequencies. The wavelength of the flagellar bending waves remains constant over the range from 10 to 40 Hz. There is a small increase in wavelength at lower frequencies; in the range of 1·5-6·2 Hz, the wavelength averaged 114% of the normal value for Ciona spermatozoa. The angle of bend of the bent regions of the flagellar bending waves remained constant within ± 10% over this range of frequencies.

2. Decapitated sperm flagella from Lytechinus beat at a continually declining frequency as they exhaust their content of ATP. Both wavelength and bend angle retain normal values until the frequency falls below about 8 Hz. Both parameters increase at lower frequencies, with a sharp increase below 3 Hz.

3. ATP-reactivated spermatozoa from Lytechinus show relatively small changes in wavelength and bend angle as the frequency is varied over the range from 5 to 25 Hz by varying the ATP concentration.

4. Constancy of wavelength over a wide range of frequencies is consistent with the hypothesis that wavelength is determined by the relative values of viscous bending resistance within a flagellum and external viscosity.

5. No satisfactory explanation is available at present for the constancy of bend angle over a wide range of frequencies nor for the changes in wave parameters which are observed at low frequencies.