BACKWARD SWIMMING MUTANT OF CHLAMYDOMONAS-REINHARDII

A backward swimming mutant (RL-10) was isolated from Chlamydomonas reinhardii. In contrast to the wild-type flagellum which usually displays a ciliary type beating pattern, the flagella in the RL-10 cells always propagated such undulating waves as found in sperm flagella. This abnormal beating pattern was maintained after the cell was demembranated by a non-ionic detergent (Nonidet P40) and reactivated with ATP. Reactivated axonemes (demembranated flagella) of the wild-type cells changed the beating pattern from the ciliary type to the flagellar type when the Ca2+ concentration was increased from 10-7 to 10-6 M. However, the RL-10 axonemes did not show such a Ca-dependent change in the beating pattern. Hence the RL-10 flagella might carry defects in the controlling mechanisms of flagellar beating pattern, at sites other than the membrane. © 1979.