Bending patterns of ATP-reactivated sea urchin sperm flagella following high salt extraction for removal of outer dynein arms.

Two procedures were used for extraction of demembranated sea urchin sperm flagella with increased KCl concentrations, to remove outer dynein arms. Extraction with 0.55 M KCl in the Triton-demembranation solution produced a rapid fall in average sliding velocity to 50% of its unextracted value, with extensive changes in bending behavior of the distal half of the flagellum. Extraction with 0.42 M KCl following demembranation and activation by incubation with cAMP produced a more gradual fall in sliding velocity, reaching 50% of the unextracted value after 180 sec extraction. This procedure produced somewhat more normal bending patterns. In both cases, the bending pattern of the basal region of the flagellum is altered very little by extraction, in agreement with data from Chlamydomonas mutant flagella deficient in outer arm dyneins.