Reactivation of Extracted Sperm 

 Cell Models in Relation to the 

 Mechanism of Motility 



DAVID W. BISHOP 



Department of Embryology, Carnegie Institution of Washington, Baltimore, Maryland 



The striking parallel in recent methods of analysis of sperm mo- 

 tility and muscnlar contraction is not coincidental. For well over 

 fifty years, attention has been directed toward the fibrillar nature of 

 the sperm tail and the analogy of flagellar activity with movement in 

 muscular systems, as testified by the statements of Ballowitz, Koltzoff, 

 Ciaccio, Heidenhain, and other classical microscopists at the turn of 

 the century (Bishop, 1962, for review). That studies of muscle took 

 a commanding lead is a tribute to the brilliance and ingenuity of 

 many able investigators, as well as to the size, distribution, charac- 

 teristics, and importance of the chosen material. That studies of 

 spermatozoa are making belated and sometimes plodding progress is 

 evidence that movement, "contractile movement," is becoming rec- 

 ognized as a universal process and some advantage is to be gained by 

 investigation of a system which may be less specialized, but is phylo- 

 genetically more ancient, than the exquisitely refined apparatus in, 

 for example, the psoas muscle of the rabbit. 



Investigations of muscular contraction have moved on a three- 

 pronged front. The physiological background has been provided par- 

 ticularly by the elegant experiments of A. V. Hill and colleagues 

 which have defined the velocity-tension-work parameters within 

 which the contractile system operates (e.g., Gasser and Hill, 1924; 

 Hill, 1938, 1949, 1950, 1958). At the other biochemical extreme, Engel- 

 hardt (1958), Szent-Gyorgyi (1951), Weber (1958), and many others 

 stimulated by them have isolated and characterized contractile pro- 

 teins from muscle fibers and have on occasion put them back. A 



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