ISOLATION OF 2 SPECIES OF CHLAMYDOMONAS-REINHARDTII FLAGELLAR MUTANTS, IDA5 AND IDA6, THAT LACK A NEWLY IDENTIFIED HEAVY-CHAIN OF THE INNERDYNEIN ARM

Two novel Chlamydomonas mutants, ida5 and ida6, that lack subsets of i nner-arm dynein have been isolated and mapped to discrete loci on the right arm of linkage group XIV. Of the seven different inner-arm dynei n subspecies (a, b, c, d, e, f and g) identified by ion-exchange chrom atography, ida5 lacks a, c, d and e, while ida6 lacks e alone; these a re the only mutants that have been shown to lack subspecies e. Both st rains can swim, albeit more slowly than the wild type. Hence, subspeci es e must contribute-to flagellar movement although it is unnecessary for the generation of undulating movement.