Mutant Strains of Chlamydomonas reinhardi1'2

Changes in the intensity of the electron spin resonaince signal of divalent manganese were found to occur in suspensions of wild-type Chlamydamonas reinhardi. The dbserved manganese signal decreased in the light and increased in the dark. Through the use of a continuous-flow system it was possiible to determlline that the manganous ions responsible for the observed, signal were localized solely in the medium. Changes in the signal intensity associated with wild-type cells were independent of the ability of fragments prepared from these cells to perform the Hill reaction with 2,6-dichlorophenol-indophenol (DPIP) as the oxidant. The manganese signal changes were still evident, though smaller, in cell suspensions of wild-type cells treated with 3-(3,4-dichlorophenyl)-1,1-dimethylurea, and in mutant strains unable to carry out the Hill reaction, ac-ii5 and ac-I4i. From these data it is concluded that the changes in intensity of the manganese resonance