title: Subcellular fractionation of the two organelle DNAs of malaria parasites.
abstract: Malaria parasites contain two extrachromosomal DNAs, a 6 kb repetitive linear molecule which is assigned on the basis of its genetic content to the mitochondria, and a 35 kb transcriptionally active circular molecule whose intracellular location is not known. We used the polymerase chain reaction to detect and estimate the numbers of both molecules in sub-cellular fractions derived from the rodent parasite Plasmodium yoelii. The two DNA molecules were not coordinately partitioned by the fractionation process, the 6 kb molecule being more abundant, relative to the 35 kb circle, in a fraction enriched for mitochondria, the converse being true for a less dense fraction of unknown identity. This implies that the two molecules are located in different cellular compartments, and is consistent with other evidence suggesting they have different evolutionary origins.
authors.affiliation: Parasitology Division, National Institute for Medical Research, Mill Hill, London, UK.
authors.forename: R J
authors.initials: RJ
authors.lastname: Wilson
authors.forename: M
authors.initials: M
authors.lastname: Fry
authors.forename: M J
authors.initials: MJ
authors.lastname: Gardner
authors.forename: J E
authors.initials: JE
authors.lastname: Feagin
authors.forename: D H
authors.initials: DH
authors.lastname: Williamson
mesh_terms: D000818:Animals; D001483:Base Sequence; D002458:Cell Fractionation; D004272:DNA, Mitochondrial / Q000302:isolation & purification*; D016054:DNA, Protozoan / Q000302:isolation & purification*; D005111:Extrachromosomal Inheritance; D008969:Molecular Sequence Data; D015388:Organelles / Q000737:chemistry*; D010967:Plasmodium yoelii / Q000235:genetics*; D016133:Polymerase Chain Reaction; D013347:Subcellular Fractions / Q000737:chemistry
chemical_list: D004272:DNA, Mitochondrial; D016054:DNA, Protozoan