Evidence for the retention of kinetoplast DNA in an acriflavine-induced dyskinetoplastic strain of Trypanosoma brucei which replicates the altered central element of the kinetoplast.

A pleomorphic dyskinetoplastic strain of Trypanosoma brucei was produced by repeated acriflavine treatment. No kinetoplastic cells reappeared after 2 yr of maintenance in the absence of acriflavine. These dyskinetoplastic cells retained and therefore replicated the central element of the kinetoplast. This element was present in the "condensed" state typical of acriflavine-treated cells rather than the normal fibrillar state. Whole-cell DNA extracted from both normal and dyskinetoplastic strains revealed three bands upon isopycnic sedimentation, and there was no detectable alteration in buoyant density of any of these DNA components in the dyskinetoplastic strain. It seems likely that the dyskinetoplastic strain has retained its kinetoplast DNA but in an altered state.