Presence of nuclear associated plasmids in the lower eukaryote Dictyostelium discoideum

High copy number plasmids have been identified in six out of 25 wild-type strains of the cellular slime mould Dictyostelium discoideum, a model organism in developmental biology (Loomis, 1982). The characterization of three plasmids, from the NC4 (Ddp1), WS380B (Ddp2) and OHIO (Ddp3) wild isolates, is presented here. We show that they are nuclear associated and non-homologous to the mitochondrial DNA and extrachromosomal ribosomal DNA.