ISSN:
0886-1544
Keywords:
spermatozoa
;
Ciona
;
axoneme
;
quiescence
;
twist
;
Life and Medical Sciences
;
Cell & Developmental Biology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
,
Medicine
Notes:
A simple planar model of sliding can predict the amount of sliding required to form a certain degree of bend. The accuracy of this prediction relies on the assumptions that no twists occur in the axoneme and that no sliding occurs at the base. However, previous studies indicated that twists may occur.This paper explores a new method for quantitating and analyzing twists. Preliminary results using this method showed that there were twists. In order to control for possible artifacts due to fixation and other preparative procedures, the characteristic S-shaped quiescent state of Ciona spermatozoa was studied.Analyses of platinum replicas of those flagella in which this waveform is well preserved suggest that most, if not all, of the twists observed are due to the artifact of a curved shape settling onto a surface. Detailed analyses indicate that if twists do occur in quiescent sperm, they are probably less than 0.4 radian. Since axonemes are evidently easily twisted in rigor, and even after fixation, caution should be exercised in interpretation of axonemal twists.
Additional Material:
9 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/cm.970030305