Detergent-Extracted Models for the Study of Cilia or Flagella

The plasma membrane of the living cell is designed to regulate the internal composition of the cytosol and protect the interior of the cell from oxidative and enzymatic damage. It performs its role so well in these respects that it presents a major obstacle to the study of intracellular processes. Recognizing this problem, Szent-Gyorgyi (1 ) used high concentrations of glycerol to increase the permeability of the membrane. This allowed him to carry out his now famous studies of skeletal muscle physiology that demonstrated the central role of ATP and Ca2+ in muscle contraction. Adopting essentially the same approach, Hoffman-Berling and Bishop (2 ,3 ) applied the glycerination method to mammalian sperm cells and reported a limited success in inducing motion but not coordinated swimming. Applying the glycerination technique to sea urchin sperm, Brokaw and Benedict (4 ) successfully restored coordinated beating of the flagellum and progressive swimming. Using the nonionic detergent Triton X-100 Gibbons and Gibbons (5 ) showed that normal flagellar motility could be reactivated in the absence of the plasma membrane. This result made it clear that the flagellar axoneme is a self-contained machine, which only requires a suitable medium and a supply of Mg-ATP to function.