title: Long-range restriction maps of Plasmodium falciparum chromosomes: crossingover and size variation among geographically distant isolates.
abstract: Homologous chromosomes from the human malaria parasite Plasmodium falciparum exhibit striking size polymorphism from isolate to isolate. To examine the structural basis for these variations, we have determined full-length restriction maps of chromosome 4 from three P. falciparum clones. Two clones, HB3 and 3D7, are derived from geographically distant strains, while the third, XP5, is the product of an HB3/3D7 cross. The restriction maps show that, while the overall structure and organization of chromosome 4 from each clone are similar, large-scale variations occur within a few hundred kilobase pairs of the chromosome ends. An apparent crossover between the 3D7 and the HB3 parent chromosomes accounts for a chromosome of intermediate size in clone XP5. Similar restriction studies extended to other parasite chromosomes will ultimately yield a long-range physical map of the P. falciparum genome.
authors.affiliation: Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, Bethesda, Maryland 20892.
authors.forename: P
authors.initials: P
authors.lastname: Sinnis
authors.forename: T E
authors.initials: TE
authors.lastname: Wellems
mesh_terms: D000818:Animals; D002874:Chromosome Mapping; D003434:Crossing Over, Genetic; D014644:Genetic Variation; D010963:Plasmodium falciparum / Q000235:genetics* / Q000302:isolation & purification; D015183:Restriction Mapping