Abstract
We isolated two strains of Chlamydomonas mutants (RL-10, RL-11) which exhibit only flagellar-type beating and which always swim back-ward. Flagella from these two mutants were similar in that they maintained their flagellar-type beating over a wide range of Ca2+ concentrations after being demembranated and reactivated in the presence of Mg-ATP. The RL-11 flagellar axoneme changed its amplitude of beating at a Ca2+ concentration of ca. 10-6 M, whereas the RL-10 axoneme showed no sensitivity to Ca2+. In temporary dikaryons of RL-10 (plus mating type) and RL-11 (minus mating type), all four flagella could beat in the normal ciliary mode, evidence that the mutations in the two strains were complementary. Electron microscopy of thin-section specimens showed no structural alterations in the mutant flagella. Several alterations in the SDS gel electrophoretic patterns of the mutant ax-onemes were found.
